Signedon both earphones: Permoflux Corp / Chicago, U.S.A.
Inscribedon both earphones: Patent pending
on top of headset: HS-23 PAL-ALT 17
on right headset, scratched: DR-PE-95-44
on left headset, scratched: DR-PE-95-34
on plug: PL-54
FunctionBetween 1940 and 1945, Harvard physicists and psychologists worked side-by-side to bring man and machine into a harmonious union. Communication equipment studied and engineered by the Electro-Acoustic Laboratory was sent to the Psycho-Acoustic Laboratory for speech articulation tests with human subjects in high-noise or low-pressure environments. Leo Beranek's and Stanley Stevens's teams developed improved microphones and earphones, and the armed forces rushed these into production.
As one can see from this example, the "patent pending" found on the headset establishes it as something new and innovative. Stevens used this improved headset to study sound transmission in a noisy environment.
ProvenancePsycho-Acoustic Laboratory , Harvard University
Published ReferencesBrandon Shackleford, When Noise Signals Change: The Electro-Acoustic and Psycho-Acoustic Laboratories from 1940 to 1945 (Senior thesis, Harvard University, 1997). CHSI Lib.4875.