Improvements in and relating to aural apparatus for the use of the deaf

摘要

423,585. Sets for deaf persons. LITTLER, T. S., 648, Wigan Road, Bryn, near Wigan. May 31, 1933, No. 15764. [Class 40 (iv)] A set for deaf persons comprises a casing a containing a thermionic amplifier, one or more microphones c mounted in or on the casing, and one or more telephone receivers i detachably connected to the casing as by plugs e1 which may also control the internal circuits. When more than one microphone is provided they may be spaced to produce a binaural effect or may have different frequency-characteristics. A volume-control device h may be included.