FR717872A
(en )
1932-01-15
Acoustic pavilion for diffusers
AT132150B
(en )
1933-03-10
Device for the photographic recording of acoustic vibrations.
CH164583A
(en )
1933-10-15
Device for transforming electric oscillations into sound vibrations or vice versa.
FR716915A
(en )
1931-12-30
Electrodynamic device intended for the transformation of electrical oscillations into acoustic vibrations or vice versa
CH122103A
(en )
1927-09-01
Device for transmitting vibrations.
AT121374B
(en )
1931-02-25
Device for the vibration-free mounting of speaking machine plates.
AT134399B
(en )
1933-07-25
Device for the photographic recording of vibrations.
SU30467A1
(en )
1933-05-31
Sound recorder
AT121484B
(en )
1931-02-25
Device for the transmission of sound vibrations.
CH152937A
(en )
1932-02-29
Device for showing optical sound films.
AT98602B
(en )
1924-11-25
Apparatus for photographic sound recording.
FR712794A
(en )
1931-10-10
Device for presenting sound films
FR707711A
(en )
1931-07-11
Sound sounding device
FR620035A
(en )
1927-04-13
Device for the production of acoustic vibrations
FR690133A
(en )
1930-09-16
Orthophone device for sound emissions
FR716223A
(en )
1931-12-17
Device intended to transform sound vibrations into electrical oscillations or vice versa
CA328159A
(en )
1932-11-29
Acoustic vibration recording apparatus
ES123184A1
(en )
1931-07-01
An apparatus of sound cinematography.
AT140658B
(en )
1935-02-25
Device for examining the ears of the hard of hearing.
ES126383A1
(en )
1932-05-16
Apparatus of sound waves.
DK46775C
(en )
1933-01-16
Device for sound reproducing apparatus.
FR658391A
(en )
1929-06-04
Underwater acoustic instrument
DK46979C
(en )
1933-02-20
Device for Underwater Signal and Sonar Devices.
GR2833B
(en )
1930-07-12
APPARATUS FOR DETERMINATION OF PULSE VIBRATIONS OF ESPECIALLY SEISMIC ORIGIN.
AT108996B
(en )
1928-02-25
Acoustic device.