DE102024207834A1 - SYSTEM AND METHOD FOR VALIDATING THE FUNCTIONAL SAFETY OF AN AUDIO MESSAGE OUTPUT IN THE INTERIOR OF A VEHICLE - Google Patents

Abstract

A system and a procedure for validating the output of an audio message in a vehicle interior are provided. A signal power modulator modulates the audio message using an audio frequency spectrum of the message as the carrier frequency and predefined modulation data. An audio generator outputs a loudspeaker tone corresponding to the modulated audio message using one or more loudspeakers in the vehicle interior. An audio recorder receives vehicle noise using one or more microphones in the vehicle interior and outputs a vehicle signal corresponding to the received vehicle noise. An extraction unit extracts estimated modulation data from the vehicle signal. A validation unit determines the difference between the estimated modulation data and the predefined modulation data and validates the audio message output if the difference is below a predefined threshold.

Description

BACKGROUND

A vehicle multimedia system can deliver an audio message to the driver or other occupants. This audio message can be a warning or instruction for the driver or other occupants. Due to circumstances (e.g., a faulty speaker), this message may not reach the vehicle occupants in time. Therefore, it can be important to validate the delivery of the safety message to the interior where the occupants are seated. If the message was not delivered in time, it can be regenerated, for example, as a visual message or again as an audio message.

The object of the invention is therefore to provide a system and a method for validating the functional safety of an audio message output in the interior of a vehicle.

SUMMARY

The object of the invention is achieved by providing a system according to claim 1 and a method according to claim 8.

• - einen Signalleistungsmodulator
• - einen Audiogenerator
• - einen Audiorekorder
• - eine Extraktionseinheit
• - eine Validierungseinheit

wobei der Signalleistungsmodulator angeordnet ist, um:

• - eine Audionachricht zu empfangen, die ein Audiospektrum mindestens einer oder mehrerer Audiofrequenzen mit einer Amplitude, die größer ist als ein Mindestwert, und mit einer beliebigen Phase aufweist;
• - die Audionachricht unter Verwendung des Audiospektrums als Trägerfrequenzen und zuvor festgelegter Modulationsdaten für die Audionachricht zu modulieren;
• - eine modulierte Audionachricht an den Audiogenerator auszugeben, die Audionachricht an die Extraktionseinheit auszugeben und die zuvor festgelegten Modulationsdaten an die Validierungseinheit auszugeben;

wobei der Audiorekorden angeordnet ist, um:

• - ein Fahrzeuggeräusch unter Verwendung eines oder mehrerer Mikrofone im Innenraum des Fahrzeugs zu empfangen;
• - ein Fahrzeugsignal, das dem empfangenen Fahrzeuggeräusch entspricht, an die Extraktionseinheit auszugeben;

wobei der Audiorekorder angeordnet ist, um:

• - ein Fahrzeuggeräusch unter Verwendung eines oder mehrerer Mikrofone im Innenraum des Fahrzeugs zu empfangen;
• - ein Fahrzeugsignal, das dem empfangenen Fahrzeuggeräusch entspricht, an die Extraktionseinheit auszugeben;

wobei die Extraktionseinheit angeordnet ist, um:

• - das Fahrzeugsignal und die Audionachricht zu empfangen;
• - geschätzte Modulationsdaten aus dem Fahrzeugsignal unter Verwendung der Audionachricht zu extrahieren;
• - die geschätzten Modulationsdaten an die Validierungseinheit auszugeben, wobei die Validierungseinheit angeordnet ist, um:
• - die geschätzten Modulationsdaten und die zuvor festgelegten Modulationsdaten zu empfangen;
• - einen Unterschied zwischen den geschätzten Modulationsdaten und den zuvor festgelegten Modulationsdaten zu bestimmen;
• - eine Ausgabe der Audionachricht zu validieren, wenn der Unterschied unterhalb einer zuvor festgelegten Schwelle liegt;
• - Validierungsdaten auszugeben, die der Validierung entsprechen.

According to a first aspect, a system for validating the functional safety of an audio message output in the interior of a vehicle is provided, the system comprising the following:

• - a signal power modulator
• - an audio generator
• - an audio recorder
• - an extraction unit
• - a validation unit

wherein the signal power modulator is arranged to:

• - to receive an audio message that has an audio spectrum of at least one or more audio frequencies with an amplitude greater than a minimum value and with any phase;
• - to modulate the audio message using the audio spectrum as carrier frequencies and previously defined modulation data for the audio message;
• - to output a modulated audio message to the audio generator, to output the audio message to the extraction unit, and to output the previously defined modulation data to the validation unit;

the audio records are arranged to:

• - to receive a vehicle sound using one or more microphones inside the vehicle;
• - to output a vehicle signal corresponding to the received vehicle noise to the extraction unit;

the audio recorder is arranged to:

• - to receive a vehicle sound using one or more microphones inside the vehicle;
• - to output a vehicle signal corresponding to the received vehicle noise to the extraction unit;

wherein the extraction unit is arranged to:

• - to receive the vehicle signal and the audio message;
• - to extract estimated modulation data from the vehicle signal using the audio message;
• - to output the estimated modulation data to the validation unit, wherein the validation unit is arranged to:
• - to receive the estimated modulation data and the previously defined modulation data;
• - to determine a difference between the estimated modulation data and the previously defined modulation data;
• - to validate an output of the audio message if the difference is below a previously defined threshold;
• - To output validation data that corresponds to the validation.

The term "functional safety validation" can refer to determining that a safety message has been transmitted, i.e., that the audio message function of providing information to the vehicle's driver has been executed. Furthermore, the volume of the transmitted audio message should be such that the driver is able to understand the information contained within it. Therefore, the volume should be above a certain minimum level and above the volume of other ambient noises around the driver.

According to the invention, the audio message includes
An audio spectrum consisting of at least one or more audio frequencies with an amplitude greater than a minimum value and with an arbitrary phase. In other words, the amplitudes of the one or more audio frequencies can be equal, but must all be above a previously defined minimum value, and the phases of the one or more audio frequencies can be of an arbitrary value.

In one or more embodiments, the audio message can comprise one or more tones, each with a specific audio frequency. In one or more embodiments, the audio message can comprise one or more spoken words.

The system according to the invention comprises a signal power modulator, an audio generator, an audio recorder, an extraction unit, and a validation unit. These can be separate devices, separate processors on a printed circuit board, or separate programs running on a single processor.

In one or more embodiments, the audio message is received by the signal power modulator from a memory located within the system. In one or more other embodiments, the audio message is received by the signal power modulator from a server located outside the vehicle, for example, via a wireless connection.

In one or more embodiments, the signal power modulator can be located outside the vehicle, and the modulation can be performed outside the vehicle and/or can be performed prior to the need for output of the audio message, for example, before the vehicle is manufactured. Subsequently, the signal power modulator can provide the modulated audio message, the audio message, and the previously defined modulation to the vehicle, where they are recorded for later use.

According to the invention, the audio message is modulated with all or part of its audio frequencies as carrier frequencies and previously defined modulation data for the audio message.

In one or more embodiments, all frequencies of the audio message above the highest frequency of the previously defined modulation data are used for demodulation. This is explained in more detail in the comprehensive description section of this document.

Due to this modulation, the validation results are more accurate and less susceptible to noise and interference (which do not normally correlate with the audio message) than the results of many prior art systems. Furthermore, the system can adjust the output to correctly validate the audio message using a shorter audio sample period than in many systems known in the prior art.

In one or more embodiments, different audio messages can be modulated with predefined modulation data. The predefined modulation data can be retrieved for each audio message from a memory contained within the system or received by the signal power modulator from a server located outside the vehicle, for example, via a wireless connection.

The audio generator receives the modulated audio message from the signal power modulator and uses one or more speakers in the vehicle to transmit the audio message to the driver and other vehicle occupants.

To determine what the occupant would be able to hear, the audio recorder can use one or more microphones to receive vehicle noise. This vehicle noise can include the speaker sound and other sounds from the vehicle itself (e.g., the engine), from the speaking occupants, and/or from outside the vehicle. The speaker sound can be distorted within the vehicle by reflections or echoes of the speaker sound and/or a defect in one or more speakers in the vehicle.

The extraction unit receives a vehicle signal corresponding to the received vehicle noise from the audio recorder and extracts estimated modulation data from the vehicle signal using the audio message received by the signal power modulator. It should be noted that the modulated audio message is not provided to the extraction unit, and it can advantageously extract estimated modulation data from the vehicle signal without using the modulated audio message.

The estimated modulation data is used by the validation unit to determine the difference between the estimated modulation data and the previously specified modulation data received by the signal power modulator. This difference can indicate how well the audio message could have been heard by the occupants, with a smaller difference indicating better transmission of the audio message.

Based on this difference, the validation unit determines whether the audio message transmission meets one or more requirements for transmitting a security message, i.e., whether the difference is below a predefined threshold. In this case, the audio message output can be considered validated. The validation unit outputs validation data indicating the results of the validation.

• - In einer oder mehreren Ausführungsformen entsprechen die zuvor festgelegten Modulationsdaten einer Modulationsfrequenz.
• - In einer oder mehreren Ausführungsformen entsprechen die zuvor festgelegten Modulationsdaten (i) periodischen Modulationsdaten, die einer periodischen Modulation entsprechen, und/oder (ii) nichtperiodischen Modulationsdaten, die einer nichtperiodischen Modulation entsprechen. Ein Vorteil dieser Kombination besteht darin, dass eine periodische Modulation hilfreich sein kann, geschätzte Modulationsdaten aus dem Fahrzeugsignal zu extrahieren.
• - In einer oder mehreren Ausführungsformen entsprechen die zuvor festgelegten Modulationsdaten Pausendaten, die Modulationspausen entsprechen. Modulationspausen können auf Zeiträume angewendet werden, in denen die Schallleistung der Audionachricht zu gering ist, um vom Audiorekorder ordnungsgemäß empfangen zu werden. Vorteile der Verwendung von Modulationspausen können darin bestehen, dass (i) eine geringe Schallleistung nicht zu einer Nichtvalidierung beiträgt und dass (ii) Modulationspausen für die Audionachricht charakteristisch sein können und somit für die Validierung verwendet werden können.

The previously defined modulation data can correspond to many different types of signal modulation or a combination thereof:

• - In one or more embodiments, the previously defined modulation data corresponds to a modulation frequency.
• In one or more embodiments, the previously defined modulation data corresponds to (i) periodic modulation data corresponding to periodic modulation, and/or (ii) non-periodic modulation data corresponding to non-periodic modulation. An advantage of this combination is that periodic modulation can be helpful in extracting estimated modulation data from the vehicle signal.
• In one or more embodiments, the previously defined modulation data corresponds to pause data, which represent modulation pauses. Modulation pauses can be applied to periods when the sound power of the audio message is too low to be properly received by the audio recorder. Advantages of using modulation pauses may be that (i) low sound power does not contribute to non-validation and (ii) modulation pauses may be characteristic of the audio message and thus be used for validation.

In one or more embodiments, the signal power modulator is further arranged to determine a minimum sound power for the modulated audio message during a previously defined power period and to transmit minimum sound power data corresponding to the minimum sound power to the The extraction unit may further be arranged to extract an estimated sound power of the vehicle noise during the previously defined performance period using the vehicle signal and to output estimated sound power data corresponding to the estimated sound power to the validation unit, wherein the validation unit is further arranged to receive the estimated sound power data and minimum sound power data and to validate the output of the audio message if the estimated sound power is equal to or higher than the minimum sound power.

One advantage of this embodiment is that it introduces a further requirement for the output of the audio message: the sound level of the audio message. This should be above a minimum level, otherwise it cannot be assumed that the occupants have heard the audio message.

In one or more embodiments, the extraction unit may further be arranged to store an inverse audio transfer function for the interior and to determine an estimated audio signal based on the vehicle signal and the audio message using the inverse audio transfer function.

The inverse audio transfer function (IAF) can indicate how a sound from the speakers inside the vehicle is distorted before being recorded by the microphones inside the vehicle. This distortion is caused by reflections within the interior and/or attenuation in the interior air. This IAF can be specific to a particular vehicle model. Using an IAF can improve the extraction of estimated modulation data.

The extraction unit can further be configured to demodulate the estimated audio signal using the audio message and optionally filter the demodulation results using a bandpass filter to obtain an estimated demodulated audio signal. The bandpass filter can allow a frequency range to pass through that includes modulation frequencies used for modulation. The extraction unit can further be configured to extract estimated modulation data from the estimated demodulated audio signal.

In one or more embodiments, the extraction unit is further arranged to extract estimated periodic modulation data from the estimated demodulated audio signal, wherein the estimated modulation data includes the estimated periodic modulation data or is extracted using the estimated periodic modulation data.

One advantage of using estimated periodic modulation data can be that it can be used as input for the extraction of non-periodic modulation data and/or as input for validation, thus making the estimated periodic modulation data part of the estimated modulation data.

In one or more embodiments, the extraction unit is further arranged to extract estimated pause data from the estimated demodulated audio signal, wherein the estimated modulation data includes the estimated pause data or is extracted using the estimated pause data.

One advantage of using estimated pause data is that it can be used as input for extracting periodic and/or non-periodic modulation data and/or as input for validation, thus making the estimated pause data part of the estimated modulation data.

In one or more embodiments, the system according to the invention can be embodied by a multimedia system of a vehicle. According to a further aspect of the invention, a vehicle is provided that includes a system for validating the functional safety of an audio message output according to any of the embodiments discussed in this document.

• - Empfangen einer Audionachricht, die ein Audiospektrum mindestens einer oder mehrerer Audiofrequenzen mit einer Amplitude, die größer ist als ein Mindestwert, und mit einer beliebigen Phase aufweist;
• - Modulieren der Audionachricht unter Verwendung des Audiofrequenzspektrums als Trägerfrequenzen und zuvor festgelegter Modulationsdaten für die Audionachricht;
• - Ausgeben eines Fahrzeugsignals, das dem empfangenen Fahrzeuggeräusch entspricht, an die Extraktionseinheit;
• - Empfangen eines Fahrzeuggeräusches unter Verwendung eines oder mehrerer Mikrofone im Innenraum des Fahrzeugs;
• - Erzeugen eines Fahrzeugsignals, das dem empfangenen Fahrzeuggeräusch entspricht;
• - Extrahieren von geschätzten Modulationsdaten aus dem Fahrzeugsignal unter Verwendung der Audionachricht;
• - Bestimmen eines Unterschieds zwischen den geschätzten Modulationsdaten und den zuvor festgelegten Modulationsdaten;
• - Validieren einer Ausgabe der Audionachricht, wenn der Unterschied unterhalb einer zuvor festgelegten Schwelle liegt;
• - Erzeugen von Validierungsdaten, die der Validierung entsprechen.

According to yet another embodiment, a method for validating the functional safety of an audio message output in the interior of a vehicle is provided, the method comprising the following steps:

• - Receiving an audio message that has an audio spectrum of at least one or more audio frequencies with an amplitude greater than a minimum value and with any phase;
• - Modulating the audio message using the audio frequency spectrum as carrier frequencies and previously defined modulation data for the audio message;
• - Outputting a vehicle signal corresponding to the received vehicle noise to the extraction unit;
• - Receiving a vehicle sound using one or more microphones inside the vehicle;
• - Generating a vehicle signal that corresponds to the received vehicle noise;
• - Extracting estimated modulation data from the vehicle signal using the audio message;
• - Determining a difference between the estimated modulation data and the previously defined modulation data;
• - Validating an audio message output if the difference is below a previously defined threshold;
• - Generating validation data that meets the validation requirements.

1. a. periodische Modulationsdaten, die einer periodischen Modulation der Audionachricht entsprechen; und
2. b. nichtperiodische Modulationsdaten, die einer nichtperiodischen Modulation der Audionachricht entsprechen; und vorzugsweise
3. c. Pausendaten, die Modulationspausen entsprechen, wobei eine Modulationspause die Abwesenheit von Modulation in einem zuvor festgelegten Zeitraum ist, wobei eine Schallleistung der Audionachricht vorzugsweise unterhalb einer zuvor definierten Schwelle liegt.

In one or more embodiments, the previously defined modulation data corresponds to a previously defined modulation frequency;
and/or the previously defined modulation data include the following:

1. a. periodic modulation data corresponding to a periodic modulation of the audio message; and
2. b. non-periodic modulation data corresponding to a non-periodic modulation of the audio message; and preferably
3. c. Pause data corresponding to modulation pauses, wherein a modulation pause is the absence of modulation during a previously defined period, wherein the sound power of the audio message is preferably below a previously defined threshold.

• - Bestimmen einer Mindestschallleistung für die modulierte Audionachricht während eines zuvor festgelegten Leistungszeitraums;
• - Erzeugen von Mindestschallleistungsdaten, die der Mindestschallleistung entsprechen, an die Validierungseinheit;
• - Extrahieren einer geschätzten Schallleistung des Fahrzeuggeräusches während des zuvor festgelegten Leistungszeitraums unter Verwendung des Fahrzeugsignals;
• - Erzeugen von geschätzten Schallleistungsdaten, die der geschätzten Schallleistung entsprechen, an die Validierungseinheit;
• - Validieren der Ausgabe der Audionachricht, wenn die geschätzte Schallleistung gleich der oder höher als die Mindestschallleistung ist.

In one or more embodiments, the method further comprises the following steps:

• - Determining a minimum sound power level for the modulated audio message during a previously defined power period;
• - Generating minimum sound power data corresponding to the minimum sound power level for the validation unit;
• - Extracting an estimated sound power level of the vehicle noise during the previously defined power period using the vehicle signal;
• - Generating estimated sound power data corresponding to the estimated sound power to the validation unit;
• - Validating the audio message output if the estimated sound power is equal to or higher than the minimum sound power.

• - Bestimmen eines geschätzten Audiosignals basierend auf dem Fahrzeugsignal und der Audionachricht unter Verwendung der inversen Audioübertragungsfunktion;
• - Demodulieren des geschätzten Audiosignals unter Verwendung der Audionachricht und optionales Filtern der Demodulationsergebnisse unter Verwendung eines Bandpassfilters, um ein geschätztes demoduliertes Audiosignal zu erhalten, wobei der optionale Bandpassfilter einen Frequenzbereich durchlässt, der für die Modulation verwendete Modulationsfrequenzen umfasst; und
• - Extrahieren von geschätzten Modulationsdaten aus dem geschätzten demodulierten Audiosignal.

In one or more embodiments, the method further comprises the following steps:

• - Determining an estimated audio signal based on the vehicle signal and the audio message using the inverse audio transfer function;
• - Demodulating the estimated audio signal using the audio message and optionally filtering the demodulation results using a bandpass filter to obtain an estimated demodulated audio signal, the optional bandpass filter allowing a frequency range to pass through that includes modulation frequencies used for modulation; and
• - Extracting estimated modulation data from the estimated demodulated audio signal.

• Extrahieren von geschätzten periodischen Modulationsdaten aus dem geschätzten demodulierten Audiosignal, wobei die geschätzten Modulationsdaten unter Verwendung der geschätzten periodischen Modulationsdaten extrahiert werden.

In one or more embodiments, the method further comprises the following step:

• Extracting estimated periodic modulation data from the estimated demodulated audio signal, wherein the estimated modulation data is extracted using the estimated periodic modulation data.

In one or more embodiments, the method further comprises the step of extracting estimated pause data from the estimated demodulated audio signal, wherein the estimated modulation data includes the estimated pause data.

According to a further aspect of the invention, a computer program is provided, wherein the computer program comprises instructions which, when executed by a computer, cause the computer to perform the steps of the method according to one of the embodiments described in this document. Furthermore, a computer-readable medium is provided on which the computer program is stored.

The functioning, advantages and embodiments of the method and the vehicle, as well as the functioning, advantages and embodiments of the computer program and the computer-readable medium, correspond to the functioning, advantages and embodiments of the method as described in this document, in the relevant application.

BRIEF DESCRIPTION OF THE DRAWINGS

• 1 einen schematischen Überblick über ein System zur Validierung der funktionalen Sicherheit einer Ausgabe einer Audionachricht in einem Innenraum eines Fahrzeugs gemäß einer oder mehreren Ausführungsformen;
• 2 einen schematischen Überblick über eine Extraktionseinheit 140 des Systems wie in 1 dargestellt;
• 3 ein Fahrzeug mit einem System zur Validierung der funktionalen Sicherheit einer Ausgabe einer Audionachricht gemäß einer oder mehreren Ausführungsformen; und
• 4 einen schematischen Überblick über ein Verfahren zur Validierung der funktionalen Sicherheit einer Ausgabe einer Audionachricht in einem Innenraum eines Fahrzeugs gemäß einer oder mehreren Ausführungsformen.

For a more complete understanding of the present invention, the following description refers to the accompanying drawings. These show:

• 1 a schematic overview of a system for validating the functional safety of an audio message output in the interior of a vehicle according to one or more embodiments;
• 2 a schematic overview of an extraction unit 140 of the system as in 1 depicted;
• 3 a vehicle with a system for validating the functional safety of an audio message output according to one or more embodiments; and
• 4 a schematic overview of a method for validating the functional safety of an audio message output in the interior of a vehicle according to one or more embodiments.

DETAILED DESCRIPTION

1 shows a schematic overview of a System 100 for validating the functional safety of an audio message output in the interior of a vehicle according to one or more embodiments.

The system 100 includes a signal power modulator 110, an audio generator 120, an audio recorder 130, an extraction unit 140 and a validation unit 150.

The signal power modulator 110 receives an audio message X, which has an audio spectrum of at least one or more audio frequencies with an amplitude greater than a minimum value and with any phase, and modulates the audio message using the audio frequency spectrum as carrier frequencies and previously specified modulation data M for the audio message X.

In one or more embodiments, all frequencies of the audio message above the highest frequency of the previously defined modulation data are used for demodulation.

• 1. $$\text{cos}\left(\text{x}\right)*\text{cos}\left(\text{y}\right)=\mathrm{0,5}*\left(\text{cos}\left(\text{x}-\text{y}\right)+\text{cos}\left(\text{x}+\text{y}\right)\right)$$
• 2. $${\text{cos}}^2\left(\text{x}\right)=\mathrm{0,5}*\left(1+\text{cos}\left(2*\text{x}\right)\right)$$
• 3. $$\text{cos}\left(\text{x}\right)=\text{cos}\left(-\text{x}\right)$$

This can be shown using the following mathematical theorems:

• 1. $$\text{cos}\left(\text{x}\right)*\text{cos}\left(\text{y}\right)=\mathrm{0,5}*\left(\text{cos}\left(\text{x}-\text{y}\right)+\text{cos}\left(\text{x}+\text{y}\right)\right)$$
• 2. $${\text{cos}}^2\left(\text{x}\right)=\mathrm{0,5}*\left(1+\text{cos}\left(2*\text{x}\right)\right)$$
• 3. $$\text{cos}\left(\text{x}\right)=\text{cos}\left(-\text{x}\right)$$

• Ωi = eine der Audiofrequenzen des Audiospektrums. Ωmin ist die niedrigste Frequenz und Qmax ist die höchste Frequenz des Audiospektrums. Die folgenden Gleichungen gelten für jegliches i.
• ω = eine Frequenz für die Datenmodulation, d. h. ω0 = 40 Hz symbolisiert eine „0“ und ω1 = 80 Hz symbolisiert eine „1“. Die höchste/niedrigste verwendete Frequenz kann als wmax bzw. wmin vermerkt werden.

The following frequencies are defined:

• Ωi = one of the audio frequencies of the audio spectrum. Ωmin is the lowest frequency and Qmax is the highest frequency of the audio spectrum. The following equations apply to any i.
• ω = a frequency for data modulation, i.e., ω0 = 40 Hz symbolizes a "0" and ω1 = 80 Hz symbolizes a "1". The highest/lowest frequency used can be noted as wmax and wmin, respectively.

Since audio frequencies within the audio spectrum can be defined by the audio message, the frequencies for data modulation should be chosen so that their ranges do not overlap. An example could be: Ωi > Ωmin > 100 Hz and ω < wmax < 100 Hz.

• 1. Erzeugen der modulierten Audionachricht Xm unter Verwendung des zuvor festgelegten Modulationssignals Ms für die Audionachricht X;
• X = Summe aller Xi mit Xi = Ai * cos(Ωi * t), wobei Ai für unterschiedliche i verschieden sein kann und verschiedene Phasen von Xi nicht berücksichtigt werden, da sie das Ergebnis bezüglich der Frequenzen nicht verändern.
• Ms = cos(ω * t), zum Beispiel mit ω0 (z. B. = 40 Hz) und ω1 (z. B. = 80 Hz), anhand derer Modulationsdaten „0“ und „1“ definiert werden.

$$\text{Xm}=\text{X}*\left(1+\text{r}*\text{Ms}\right)\text{mit r}=\text{Modulationsfaktor}$$ Below, an example of modulation and demodulation according to one or more embodiments of the invention is mathematically proven:

• 1. Generating the modulated audio message Xm using the previously defined modulation signal Ms for the audio message X;
• X = sum of all Xi with Xi = Ai * cos(Ωi * t), where Ai can be different for different i and different phases of Xi are not taken into account, as they do not change the result with respect to the frequencies.
• Ms = cos(ω * t), for example with ω0 (e.g. = 40 Hz) and ω1 (e.g. = 80 Hz), which define the modulation data “0” and “1”.

$$\text{Xm}=\text{X}*\left(1+\text{r}*\text{Ms}\right)\text{mit r}=\text{Modulationsfaktor}$$

For each Xi, the following equation applies: $$\begin{array}{c}\text{Xmi}=\text{Ai}*\text{cos}\left(\mathrm{\Omega }\text{i}*\text{t}\right)*\left(1+\text{r}*\text{cos}\left(\mathrm{\omega }*\text{t}\right)\right)\\ =\text{Ai}*\text{cos}\left(\mathrm{\Omega }\text{i}*\text{t}\right)+\mathrm{0,5}*\text{Ai}*\text{r}*(\text{cos}((\mathrm{\Omega }\text{i}+\mathrm{\omega })\text{t})+\text{cos}\left(\left(\mathrm{\Omega }\text{i}-\mathrm{\omega }\right)\text{t})\right)\end{array}$$

• 2. Demodulation von XXm mit X für alle Xi

The following can take place in the extraction unit:

• 2. Demodulation of XXm with X for all Xi

In a first step, the signal XXm is calculated as follows: XXm = X*Xm. The resulting signal XXm is then filtered for ω0 (e.g., = 40 Hz) and for ω1 (e.g., = 80 Hz).

If the signal power of XXm is above a previously defined threshold and the filtered signal for ω0 is larger than for ω1, a “0” (otherwise a “1”) is generated as estimated modulation data Mc.

It can be shown that XXm contains the modulation signal M = cos(ω * t) with ω = ω0 (e.g., = 40 Hz) and ω = ω1 (e.g., = 80 Hz) for each Xmi. It is assumed that the extraction unit can perfectly reconstruct the modulated audio message Xm from the vehicle signal Ym.

The audio power output of X and Xmi is calculated as follows: $$\begin{array}{l}\text{XXmi}=\text{Xi}*\text{Xmi}\\ =\text{Ai}*\text{cos}\left(\mathrm{\Omega }\text{i}*\text{t}\right)*\left(\text{Ai}*\text{cos}\left(\mathrm{\Omega }\text{i}*\text{t}\right)+\mathrm{0,5}*\text{Ai}*\text{r}(\text{cos}((\mathrm{\Omega }\text{i}+\mathrm{\omega })\text{t}\right)+\text{cos}(\left(\mathrm{\Omega }\text{i}-\mathrm{\omega }\right)\\ \text{t}))\\ =\mathrm{0,5}*{\left(\text{Ai}\right)}^2*\left(1+\text{cos}\left(2*\mathrm{\Omega }\text{i}*\text{t}\right)\right)+\mathrm{0,5}*{\left(\text{Ai}\right)}^2*\text{r}*\text{cos}\left(\mathrm{\Omega }\text{i}*\text{t}\right)*\left(\text{cos}(\left(\mathrm{\Omega }\text{i}+\mathrm{\omega }\right)\text{t}\right)\\ +\text{cos}\left(\left(\mathrm{\Omega }\text{i}-\mathrm{\omega }\right)\text{t}\right))\\ =\mathrm{0,5}*{\left(\text{Ai}\right)}^2*\left(1+\text{cos}\left(2*\mathrm{\Omega }\text{i}*\text{t}\right)\right)+\mathrm{0,5}*{\left(\text{Ai}\right)}^2*\text{r}*\mathrm{0,5}*\left(\text{cos}\left(\left(\mathrm{\Omega }\text{i}+(\mathrm{\Omega }\text{i}+\mathrm{\omega }\right)\right)*\text{t}\right)\\ +\text{cos}\left(\left(\mathrm{\Omega }\text{i}-(\mathrm{\Omega }\text{i}+\mathrm{\omega }\right)\right)*\text{t})+\text{cos}\left(\left(\mathrm{\Omega }\text{i}+(\mathrm{\Omega }\text{i}-\mathrm{\omega }\right)\right)*\text{t})+\text{cos}\left(\left(\mathrm{\Omega }\text{i}-\left(\mathrm{\Omega }\text{i}-\mathrm{\omega }\right)\right)*\text{t}\right))\\ =\mathrm{0,5}*{\left(\text{Ai}\right)}^2*\left(1+\text{cos}\left(2*\mathrm{\Omega }\text{i}*\text{t}\right)\right)+\mathrm{0,25}*{\left(\text{Ai}\right)}^2*\text{r}*\left(\text{cos}(\left(2*\mathrm{\Omega }\text{i}+\mathrm{\omega }\right)*\text{t}\right)+\text{cos}(-\\ \mathrm{\omega }*\text{t})+\text{cos}\left(\left(2*\mathrm{\Omega }\text{i}-\mathrm{\omega }\right)\right)*\text{t})+\text{cos}\left(\mathrm{\omega }*\text{t}\right))\\ =\mathrm{0,5}*{\left(\text{Ai}\right)}^2*\left(1+\text{cos}\left(2*\mathrm{\Omega }\text{i}*\text{t}\right)\right)+\mathrm{0,25}*{\left(\text{Ai}\right)}^2*\text{r}*\text{cos}\left(\left(2*\mathrm{\Omega }\text{i}+\mathrm{\omega }\right)*\text{t}\right)+\\ \mathrm{0,25}*{\left(\text{Ai}\right)}^2*\text{r}*\text{cos}\left(\left(2*\mathrm{\Omega }\text{i}-\mathrm{\omega }\right)*\text{t}\right))+\mathrm{0,5}*{\left(\text{Ai}\right)}^2*\text{r}*\text{cos}\left(\mathrm{\omega }*\text{t}\right))\end{array}$$ $$$$

• Der Term: 0,5 * (Ai)² * (1 + cos(2 * Ωi * t)) weist eine konstante Komponente und eine alternierende Komponente mit dem 2-Fachen der Audiosignalfrequenz auf. Beide können leicht herausgefiltert werden, da ihre Frequenz = 0 und > Ωmin. Dieser Term trägt keine Modulationsdaten.
• Der Term: 0,25 * (Ai)² * r * cos((2*Ωi + ω) * t) ist eine Mischung von Audionachrichtfrequenzen und einem Modulationsdatensignal. Er kann leicht herausgefiltert werden, da seine Frequenz 2*Ωi + ω > Ωmin beträgt. Der Term: 0,25 * (Ai)² * r * cos((2*Ωi - ω) * t)) ist ebenfalls eine Mischung von Audionachrichtfrequenzen und einem Modulationsdatensignal. Er kann herausgefiltert werden, da seine Frequenz 2*Ωi - ω > 2* Ωmin - wmax > Ω min beträgt.
• Der Term: 0,5* (Ai)² * r * cos(ω * t)) ist das interessante Ergebnis, das genau die Frequenz des Modulationsdatensignals trägt. Er kann mit einem Tiefpassfilter mit einer Grenzfrequenz < Ωmin gefiltert werden. Anschließend kann er weiter untersucht werden.

Discussion of the result:

• The expression: 0.5 * (Ai) ² * (1 + cos(2 * Ωi * t)) has a constant component and an alternating component with twice the audio signal frequency. Both can be easily filtered out since their frequency = 0 and > Ωmin. This expression carries no modulation data.
• The term: 0.25 * (Ai) ² * r * cos((2*Ωi + ω) * t) is a mixture of audio message frequencies and a modulation data signal. It can be easily filtered out because its frequency 2*Ωi + ω > Ωmin. The term: 0.25 * (Ai) ² * r * cos((2*Ωi - ω) * t)) is also a mixture of audio message frequencies and a modulation data signal. It can be filtered out because its frequency 2*Ωi - ω > 2*Ωmin - wmax > Ωmin.
• The term 0.5 * (Ai) ^² * r * cos(ω * t)) is the interesting result, as it carries the exact frequency of the modulation data signal. It can be filtered with a low-pass filter with a cutoff frequency < Ωmin. It can then be further investigated.

In one or more embodiments, the previously defined modulation data M corresponds to a previously defined modulation frequency. In one or more embodiments, the previously defined modulation data M comprises periodic and non-periodic modulation data corresponding to periodic and non-periodic modulation of the audio message X. The previously defined modulation data M may further comprise pause data corresponding to modulation pauses.

A modulation pause is an absence of modulation during a predetermined period, where the sound power of the audio message X is preferably below a predetermined threshold.

Since the human ear and brain have limitations regarding the processing of sounds, the previously determined modulation data should be chosen so that the occupants are not aware of the fact that the audio message was modulated using previously determined modulation data, or are not disturbed by it.

The signal power modulator 110 outputs a modulated audio message Xm to the audio generator 120, which in turn outputs the audio message X to the extraction unit 140. The signal power modulator 110 also outputs predefined modulation data M to the validation unit 150.

In one or more embodiments, the signal power modulator 110 determines a minimum sound power for the modulated audio message Xm during a previously defined power period and outputs minimum sound power data Px corresponding to the minimum sound power to the validation unit 150.

The audio generator 120 receives the modulated audio message Xm and outputs a loudspeaker tone corresponding to the modulated audio message Xm using one or more loudspeakers 301 in the vehicle interior. The audio generator 120 can be configured to convert the modulated audio message Xm into an analog electrical signal Xn for the one or more loudspeakers 301. In one or more embodiments, the one or more loudspeakers can be incorporated into the audio generator.

The audio recorder 130 receives vehicle sound using one or more microphones 303 inside the vehicle. The speaker sound can be received directly from the one or more speakers 301 and/or via reflections of the sound from surfaces 302 inside the vehicle. In addition to the speaker sound, the audio recorder 130 can also record ambient sounds N generated outside and/or outside the vehicle.

The audio recorder 130 can receive an analog electrical signal Yn from one or more microphones 303. The audio recorder 130 outputs a vehicle signal Ym, corresponding to the received vehicle noise, to the extraction unit 140.

2 shows a schematic overview of an extraction unit 140 of the system as in 1 shown. In one or more embodiments, the extraction unit 140 can comprise a room acoustic compensator 210 and/or a demodulator 220.

The room acoustic compensator 210 can store an inverse audio transfer function (InvGxy) for the vehicle interior. The audio transfer function Gxy can be determined from the relationship between the cross-power density Sxy of X and Ym and the car's power density Sxx of X. Subsequently, the impulse response of the room or interior can be calculated by converting Gx into the time domain, which represents the room's sound reflections or echoes. To compensate for these reflections, the audio transfer function Gxy is inverted to obtain the inverse audio transfer function (InvGxy = 1/Gxy). However, other methods besides those known in the prior art can also be used to determine the inverse audio transfer function InvGxy.

The inverse audio transfer function (InvGxy) can then be used as a filter to extract the estimated audio signal Xs from the vehicle signal Ym. The room acoustic compensator 210 can then output the estimated audio signal Xs to the demodulator 220.

The demodulator 220 can demodulate and filter the estimated audio signal Xs using the audio message X and a bandpass filter to obtain an estimated demodulated audio signal XXs. The bandpass filter can be configured to allow a frequency range to pass through that includes the modulation frequencies used for modulation. The extraction unit 140 can further be configured to extract estimated modulation data Mc from the estimated demodulated audio signal XXs.

In one or more embodiments, the extraction unit 140 may further comprise a modulation synchronization unit 230 and a modulation data estimation unit 240.

The modulation synchronization unit 230 is configured to determine an estimated periodic modulation Mb in the estimated demodulated audio signal XXs. The modulation synchronization unit 230 can further be configured to determine estimated modulation pauses Mp in the estimated demodulated audio signal XXs. Furthermore, the modulation synchronization unit 230 can be configured to output the estimated periodic modulation Mb and, optionally, the estimated modulation pauses Mp to the modulation data estimation unit 240.

The modulation data estimation unit 240 uses the estimated demodulated audio signal XXs to determine estimated modulation data Mc. For this purpose, the modulation data estimation unit 240 can further be configured to use the estimated periodic modulation Mb and/or the estimated modulation pauses Mp.

In one or more embodiments, the extraction unit 140 or, more specifically, the modulation data estimation unit 240 is further arranged to extract an estimated sound power of the vehicle noise during the previously defined power period using the vehicle signal Ym or the estimated demodulated audio signal XXs.

The extraction unit 140 outputs the estimated modulation data Mc and optionally the estimated sound power data Pm, which correspond to the estimated sound power, to the validation unit 150.

As from 1 As can be seen, the validation unit 150 receives the estimated modulation data Mc and the previously defined modulation data M. The validation unit 150 determines the difference between the estimated modulation data Mc and the previously defined modulation data M and validates the audio message output if the difference is below a previously defined threshold. The validation unit 150 outputs validation data that corresponds to the validation.

In one or more embodiments, after the output of the audio message has not been validated, the system 100 can restart the validation of an output of an audio message in which the audio message is output again, based on the validation data.

In one or more embodiments, the system 100 further comprises a display 160. The display 160 can be arranged to show a visual message to the vehicle occupants based on the validation data. The visual message can visually indicate the content of the audio message, preferably using symbols and/or letters if the audio message output has not been validated.

3 Figure 310 shows a vehicle 310 with a system 100 for validating the functional safety of an audio message output according to one or more embodiments as described in this document. The vehicle 310 may further include one or more loudspeakers 303 located in the interior of the vehicle 310 and/or one or more microphones 301 located in the interior of the vehicle 310. In one or more embodiments, the vehicle 310 may be a car, motorcycle, van, truck, bicycle, or scooter. In one or more embodiments, the system 100 may be part of the infotainment system of the vehicle 310.

4 shows a schematic overview of a method 400 for validating the functional safety of an audio message output in the interior of a vehicle according to one or more embodiments.

• [410] Empfangen einer Audionachricht X, die ein Audiospektrum mindestens einer oder mehrerer Audiofrequenzen mit einer Amplitude Ai, die größer ist als ein Mindestwert, und mit einer beliebigen Phase aufweist;
• [420] Modulieren der Audionachricht X unter Verwendung des Audiospektrums als Trägerfrequenzen und zuvor festgelegter Modulationsdaten für die Audionachricht;
• [430] Ausgeben eines Lautsprechertons, der der modulierten Audionachricht Xm entspricht, unter Verwendung eines oder mehrerer Lautsprecher im Innenraum des Fahrzeugs 310;
• [440] Empfangen eines Fahrzeuggeräusches unter Verwendung eines oder mehrerer Mikrofone im Innenraum des Fahrzeugs 310;
• [450] Erzeugen eines Fahrzeugsignals Ym, das dem empfangenen Fahrzeuggeräusch entspricht;
• [460] Extrahieren von geschätzten Modulationsdaten Mc aus dem Fahrzeugsignal Ym unter Verwendung der Audionachricht X;
• [470] Bestimmen eines Unterschieds zwischen den geschätzten Modulationsdaten und den zuvor festgelegten Modulationsdaten;
• [480] Validieren einer Ausgabe der Audionachricht, wenn der Unterschied unterhalb einer zuvor festgelegten Schwelle liegt; und
• [490] Erzeugen von Validierungsdaten, die der Validierung entsprechen.

Procedure 400 comprises the following steps:

• [410] Receiving an audio message X which has an audio spectrum of at least one or more audio frequencies with an amplitude Ai greater than a minimum value and with any phase;
• [420] Modulating the audio message X using the audio spectrum as carrier frequencies and previously defined modulation data for the audio message;
• [430] Outputting a loudspeaker tone corresponding to the modulated audio message Xm using one or more loudspeakers inside the vehicle 310;
• [440] Receiving a vehicle sound using one or more microphones inside the vehicle 310;
• [450] Generating a vehicle signal Ym corresponding to the received vehicle noise;
• [460] Extracting estimated modulation data Mc from the vehicle signal Ym using the audio message X;
• [470] Determining a difference between the estimated modulation data and the previously determined modulation data;
• [480] Validating an output of the audio message if the difference is below a previously set threshold; and
• [490] Generating validation data that corresponds to the validation.

1. a. periodische Modulationsdaten, die einer periodischen Modulation der Audionachricht X entsprechen; und
2. b. nichtperiodische Modulationsdaten, die einer nichtperiodischen Modulation der Audionachricht X entsprechen; und vorzugsweise
3. c. Pausendaten, die Modulationspausen entsprechen, wobei eine Modulationspause eine Abwesenheit von Modulation in einem zuvor festgelegten Zeitraum ist, wobei eine Schallleistung der Audionachricht X vorzugsweise unterhalb einer zuvor definierten Schwelle liegt.

In one or more embodiments, the previously defined modulation data M corresponds to a previously defined modulation frequency, and/or wherein the previously defined modulation data M comprises the following:

1. a. periodic modulation data corresponding to a periodic modulation of the audio message X; and
2. b. non-periodic modulation data corresponding to a non-periodic modulation of the audio message X; and preferably
3. c. Pause data corresponding to modulation pauses, wherein a modulation pause is an absence of modulation for a previously defined period, wherein the sound power of the audio message X is preferably below a previously defined threshold.

• [510] Bestimmen einer Mindestschallleistung Px für die modulierte Audionachricht Xm während eines zuvor festgelegten Leistungszeitraums;
• [520] Erzeugen von Mindestschallleistungsdaten, die der Mindestschallleistung Px entsprechen, an die Validierungseinheit;
• [530] Extrahieren einer geschätzten Schallleistung Pm des Fahrzeuggeräusches während des zuvor festgelegten Leistungszeitraums unter Verwendung des Fahrzeugsignals Ym;
• [540] Erzeugen von geschätzten Schallleistungsdaten, die der geschätzten Schallleistung Pm entsprechen, an die Validierungseinheit;
• [550] Validieren der Ausgabe der Audionachricht, wenn die geschätzte Schallleistung Pm gleich der oder höher als die Mindestschallleistung Px ist.

In one or more embodiments, the method further comprises the following steps:

• [510] Determining a minimum sound power Px for the modulated audio message Xm during a previously defined power period;
• [520] Generating minimum sound power data corresponding to the minimum sound power Px to the validation unit;
• [530] Extracting an estimated sound power Pm of the vehicle noise during the previously determined power period using the vehicle signal Ym;
• [540] Generating estimated sound power data corresponding to the estimated sound power Pm to the validation unit;
• [550] Validating the output of the audio message when the estimated sound power Pm is equal to or higher than the minimum sound power Px.

• [610] Bestimmen eines geschätzten Audiosignals Xs basierend auf dem Fahrzeugsignal Ym und der Audionachricht X unter Verwendung der inversen Audioübertragungsfunktion InvGxy;
• [620] Demodulieren des geschätzten Audiosignals unter Verwendung der Audionachricht und optionales Filtern der Demodulationsergebnisse unter Verwendung eines Bandpassfilters, um ein geschätztes demoduliertes Audiosignal zu erhalten, wobei der optionale Bandpassfilter einen Frequenzbereich durchlässt, der für die Modulation verwendete Modulationsfrequenzen umfasst; und
• [630] Extrahieren von geschätzten Modulationsdaten Mc aus dem geschätzten demodulierten Audiosignal XXs.

In one or more embodiments, the method further comprises the following steps:

• [610] Determining an estimated audio signal Xs based on the vehicle signal Ym and the audio message X using the inverse audio transfer function InvGxy;
• [620] Demodulating the estimated audio signal using the audio message and optionally filtering the demodulation results using a bandpass filter to obtain an estimated demodulated audio signal, wherein the optional bandpass filter allows a frequency range to pass through that includes modulation frequencies used for modulation; and
• [630] Extracting estimated modulation data Mc from the estimated demodulated audio signal XXs.

• [710] Verfahren nach Anspruch 11, das ferner den folgenden Schritt umfasst: Extrahieren von geschätzten periodischen Modulationsdaten Mb aus dem geschätzten demodulierten Audiosignal XXs, wobei die geschätzten Modulationsdaten Mc unter Verwendung der geschätzten periodischen Modulationsdaten Mb extrahiert werden; und/oder
• [720] Extrahieren von geschätzten Pausendaten Mp aus dem geschätzten demodulierten Audiosignal XXs, wobei die geschätzte Modulation Mc die geschätzten Pausendaten Mp umfasst.

In one or more embodiments, the method further comprises the following steps:

• [710] The method of claim 11, further comprising the following step: extracting estimated periodic modulation data Mb from the estimated demodulated audio signal XXs, wherein the estimated modulation data Mc are extracted using the estimated periodic modulation data Mb; and/or
• [720] Extracting estimated pause data Mp from the estimated demodulated audio signal XXs, wherein the estimated modulation Mc includes the estimated pause data Mp.

It is clear to those skilled in the art that the various illustrative logic blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above in general terms with regard to their functionality. Whether such functionality is implemented as hardware or software depends on the specific application(s) and design-related constraints to which the overall system is subject. Skilled in the art may implement the described functionality in different ways for each specific application; however, such implementation decisions should not be construed as resulting in a deviation from the scope of the present invention.

The foregoing description of the disclosed embodiments is provided so that any person skilled in the art can carry out or use the present invention. Various modifications of these embodiments are obvious to those skilled in the art, and the overarching principles defined herein can be applied to other embodiments without departing from the spirit or scope of the invention. The present invention is therefore not intended to be limited to the embodiments shown herein. its being, but it is to be granted the widest possible scope that is compatible with the principles and novel features disclosed herein.

The benefits and advantages that can be provided by the present invention have been described above with reference to specific embodiments. These benefits and advantages, as well as any elements or limitations that may cause them to occur or enhance them, are not to be construed as critical, necessary, or essential features of any or all of the claims. As used herein, the terms "includes," "comprehensive," or any other form thereof are to be understood as encompassing not exclusively the elements or limitations that follow these terms. Accordingly, a system, method, or other embodiment comprising a group of elements is not limited to these elements but may include other elements not expressly stated or inherent in the claimed embodiment.

Although the present invention has been described with reference to specific embodiments, it is understood that these embodiments are for illustrative purposes only and that the scope of the invention is not limited to these embodiments. Many variations, modifications, additions, and improvements are possible with respect to the embodiments described above. It is intended that these variations, modifications, additions, and improvements fall within the scope of the invention, as detailed in the following claims.

Claims (15)

System for validating the functional safety of an audio message output in the interior of a vehicle, the system comprising: - a signal power modulator - an audio generator - an audio recorder - an extraction unit - a validation unit where the signal power modulator is configured to: - receive an audio message (X) having an audio spectrum of at least one or more audio frequencies with an amplitude greater than a minimum value and with any phase; - modulate the audio message using the audio frequency spectrum as carrier frequencies and predefined modulation data (M) for the audio message (X); - output a modulated audio message (Xm) to the audio generator, output the audio message to the extraction unit, and output the predefined modulation data (M) to the validation unit; where the audio recorder is configured to: - receive the modulated audio message (Xm); - to output a loudspeaker tone corresponding to the modulated audio message (Xm) using one or more loudspeakers in the vehicle interior; the audio recorder is configured to: - receive a vehicle sound using one or more microphones in the vehicle interior; - output a vehicle signal (Ym) corresponding to the received vehicle sound to the extraction unit; the extraction unit is configured to: - receive the vehicle signal (Ym) and the audio message (X); - extract estimated modulation data (Mc) from the vehicle signal (Ym) using the audio message (X); - output the estimated modulation data (Mc) to the validation unit, the validation unit being configured to: - receive the estimated modulation data (Mc) and the previously specified modulation data (M); - determine a difference between the estimated modulation data (Mc) and the previously specified modulation data (M); - Validate an audio message output if the difference is below a predefined threshold; Output validation data corresponding to the validation. System according Claim 1 , - wherein the previously specified modulation data (M) correspond to a previously specified modulation frequency; and/or - wherein the previously specified modulation data (M) comprise: ◯ periodic modulation data corresponding to a periodic modulation of the audio message (X); and ◯ non-periodic modulation data corresponding to a non-periodic modulation of the audio message (X); and preferably ◯ pause data corresponding to modulation pauses, wherein a modulation pause is an absence of modulation for a previously specified period, wherein a sound power of the audio message (X) is preferably below a previously defined threshold. System according to any of the preceding claims, wherein the signal power modulator is further arranged to: - determine a minimum sound power for the modulated audio message (Xm) during a predetermined power period; - output minimum sound power data (Px) corresponding to the minimum sound power to the validation unit; wherein the extraction unit is further arranged to: - extract an estimated sound power (Pm) of the vehicle noise during the predetermined power period using the vehicle signal (Ym); - output estimated sound power data corresponding to the estimated sound power (Pm) to the validation unit; wherein the validation unit is further arranged to: - receive the estimated sound power data and the minimum sound power data; - validate the output of the audio message if the estimated sound power (Pm) is equal to or greater than the minimum sound power (Px). System according to any of the preceding claims, wherein the extraction unit is further arranged to: - store an inverse audio transfer function (InvGxy) for the interior; - determine an estimated audio signal (Xs) based on the vehicle signal (Ym) and the audio message (X) using the inverse audio transfer function (InvGxy); - demodulate the estimated audio signal using the audio message and optionally filter the demodulation results using a bandpass filter to obtain an estimated demodulated audio signal, wherein the optional bandpass filter passes a frequency range that includes modulation frequencies used for modulation; and - extract estimated modulation data (Mc) from the estimated demodulated audio signal (XXs). System according Claim 4 depending on Claim 2 , wherein the extraction unit is further arranged to: - extract estimated periodic modulation data (Mb) from the estimated demodulated audio signal (XXs); wherein the estimated modulation data (Mc) are extracted using the estimated periodic modulation data (Mb). system according to one of the Claims 4 - 5 depending on Claim 2 , wherein the extraction unit is further arranged to: - extract estimated pause data (Mp) from the estimated demodulated audio signal (XXs); wherein the estimated modulation data (Mc) are extracted using the estimated pause data (Mp). Vehicle that has a system for validating the functional safety of an audio message output according to one of the Claims 1 - 6 includes. A method for validating the functional safety of an audio message output in the interior of a vehicle, comprising the following steps: - Receiving an audio message (X) having an audio spectrum of at least one or more audio frequencies with an amplitude greater than a minimum value and with an arbitrary phase; - Modulating the audio message using the audio frequency spectrum as carrier frequencies and previously defined modulation data (M) for the audio message (X); - Output of a loudspeaker tone corresponding to the modulated audio message (Xm) using one or more loudspeakers inside the vehicle; - Receiving a vehicle sound using one or more microphones inside the vehicle; - Generating a vehicle signal (Ym) corresponding to the received vehicle sound; - Extracting estimated modulation data (Mc) from the vehicle signal (Ym) using the audio message (X); - Determining the difference between the estimated modulation data (Mc) and the previously defined modulation data (M); - Validating an output of the audio message if the difference is below a previously defined threshold; - Generating validation data corresponding to the validation. Procedure according to Claim 8 , wherein the previously specified modulation data (M) correspond to a previously specified modulation frequency; and/or wherein the previously specified modulation data (M) comprise: a. periodic modulation data corresponding to periodic modulation of the audio message (X); and b. non-periodic modulation data corresponding to non-periodic modulation of the audio message (X); and preferably c. pause data corresponding to modulation pauses, wherein a modulation pause is an absence of modulation for a previously specified period, wherein a sound power of the audio message (X) is preferably below a previously defined threshold. Procedure according to one of the Claims 8 - 9 , which further comprises the following steps: - Determining a minimum sound power (Px) for the modulated audio message (Xm) during a previously defined power period; - Generating minimum sound power data corresponding to the minimum sound power (Px) to the validation unit; - Extracting an estimated sound power (Pm) of the vehicle noise during the previously defined power period using the vehicle signal (Ym); - Generating estimated sound power data corresponding to the estimated sound power (Pm) to the validation unit; - Validating the output of the audio message if the estimated sound power (Pm) is equal to or higher than the minimum sound power (Px). Procedure according to one of the Claims 8 - 10 , which further comprises the following steps: - Determining an estimated audio signal (Xs) based on the vehicle signal (Ym) and the audio message (X) using the inverse audio transfer function (InvGxy); - Demodulating the estimated audio signal using the audio message and optionally filtering the demodulation results using a bandpass filter to obtain an estimated demodulated audio signal, the optional bandpass filter allowing a frequency range to pass through that includes modulation frequencies used for modulation; and - Extracting estimated modulation data (Mc) from the estimated demodulated audio signal (XXs). Procedure according to Claim 11 , which further includes the following step: Extracting estimated periodic modulation data (Mb) from the estimated demodulated audio signal (XXs), wherein the estimated modulation data (Mc) is extracted using the estimated periodic modulation data (Mb). Procedure according to Claim 11 , which further includes the following step: extracting estimated pause data (Mp) from the estimated demodulated audio signal (XXs), wherein the estimated modulation (Mc) includes the estimated pause data (Mp). A computer program that includes instructions which, when executed by a computer, cause the computer to perform the steps of the procedure according to one of the Claims 1 - 7 carries out. Computer-readable medium on which the computer program is stored. Claim 14 is stored.