Digitally programmable hearing aid - has electronic switch operated by programmable memory for selective use of programming socket as alternative source of audio input

摘要

The microphone (1) is connected to the earphone (3) by an audio amplifier circuit (2) subject to vol. and tone controls from a digitally programmable nonvolatile memory (4), which has a two-pin socket (5) for connection to an external programmer. A control line (7) from the memory (4) operates an electronic switch (6) which opens and closes a direct connection from the programming socket (5) to the amplifier (2). The switching may be performed by special data signals to the gate of an FET. ADVANTAGE - Electrical signals can be connected from external sound sources directly to audio amplifier.