New Hearing Aid with Microphone Array System

Many hearing aids now feature pre-installed microphone array directional acoustic receiving systems. The system is designed like a necklace with an array of two or more microphones integrated on a frame and placed on the user’s chest with a conducting loop around the neck.

The frame has signal processing electronics that receive and combine microphone signals in a way that provides an amplified output signal to intensify sounds of primary interest and those arriving forward-facing rather than from the background.

An electro-acoustic transducer with a magnetic field pick-up coil is mounted to the user’s ear. It picks up magnetic fields and produces acoustic signals of sounds of primary interest. The output signals are measured and combined to accomplish the desired directivity responses. The scaled microphone signals are filtered and given a directivity pattern, which remains uniform over frequency in two or three dimensions. This process facilitates development of such sophisticated directive hearing instruments that are convenient and comfortable to use.

In comparison to the existing hearing machines, the array significantly improves speech perception especially in places with noise and disturbances.

Source: Circuits and Systems Magazine.