The 17MIT series Miniature Inertial Transducers are high performance bone conduction microphones for use in direct contact with the user's skull or neck. Unlike many bone conduction microphones, particularly piezoelectric types, which exhibit a single frequency peak around 1200Hz, the 17MIT has a response from 300Hz to 10kHz. Reproduced speech is therefore clear with good reproduction of harmonic frequencies. Due to the nature of the device, it provides a high level of ambient noise rejection without the need for electronic noise cancellation. When correctly mounted it provides clear voice communications in ambient noise levels of up to 120dB SPL.

Electrically the device looks similar to a dynamic microphone, normally with an impedance of 2000 ohms. Although it's frequency response is relatively flat, the response of the human skull is not and the sound picked up from the skull has quite different spectral content depending on the location of the microphone. From a practical perspective it is necessary to compensate for the effect of the skull and this is normally be achieved by use of an interface amplifier. Depending on the application, such amplifiers can either be built into the microphone housing or be housed externally. The microphones can be supplied either with or without a integral amplifier. The units with an integral amplifier can be powered from an electret microphone supply and effectively appear as an electret microphone. We can supply either microphones or headset, headband, and in-helmet products incorporating the microphone.