Improvement and evaluation of the vibration pick-up-type ear microphone and two-way communication device
Hiroshi Ono · The Journal of the Acoustical Society of America · 1977
A vibration pick-up-type ear microphone was developed as an alternative to the conventional sound-pressure-type ear microphone. It was evaluated and compared to other conventional microphones with the following results: It is possible to obtain remarkable sensibility without closing the ear canal and to obtain speech intelligibility scores of over 95%. There was no significant difference between voice intelligibility with a mask and without a mask. Speech intelligibility of the vibration pick-up-type ear microphone in high ambient noise is much higher (110 dB—96%, 125 dB—84%) than that of a noise canceling microphone (110 dB—87%, 125 dB—77%) and of a sound-pressure-type ear microphone with ear muff (110 dB—85%, 125 dB—68%). By using the two-way communication device it is possible to talk and to listen simultaneously since the ear canal is not obstructed. The vibration pick-up-type ear-insert microphone can be used (1) for voice communication in high ambient noise, (2) in a mask, (3) for hands-free operations, and (4) it will not howl due to excessive feedback. Communication systems using the vibration pick-up-type ear microphone have been evaluated in various environments.