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Filing date
Publication date
Application filedfiledCritical
Priority to JP6754375ApriorityCriticalpatent/JPS51144105A/ja
Publication of JPS51144105ApublicationCriticalpatent/JPS51144105A/ja
Publication of JPS5439088B2publicationCriticalpatent/JPS5439088B2/ja
H04M1/00—Substation equipment, e.g. for use by subscribers
H04M1/02—Constructional features of telephone sets
H04M1/19—Arrangements of transmitters, receivers, or complete sets to prevent eavesdropping, to attenuate local noise or to prevent undesired transmission; Mouthpieces or receivers specially adapted therefor
Landscapes
Engineering & Computer Science
(AREA)
Signal Processing
(AREA)
Headphones And Earphones
(AREA)
Obtaining Desirable Characteristics In Audible-Bandwidth Transducers
(AREA)