Some specific characteristics of vibration pickup type auditory canal microphones
Yoshinori Miyawaki, Shinsaku Mori, Hiroshi One, Shigeji Saito · The Journal of the Acoustical Society of America · 1975
In high-noise environments, we cannot sufficiently transmit voice signals by the usual transducers. Therefore, we have developed a vibration pickup-type microphone (acceleration type) and propose that communications be exchanged using this method. We chose the auditory canal in order to equip this microphone easily. In this investigation, we (1) compared a vibration pickup-type auditory canal microphone with a noise-canceling microphone focusing on their ability to shut noise out; and (2) compared an air-conduction spectrum caught by a handy microphone with a bone-conduction spectrum caught by the vibration pickup-type used in Experiment 1. When subjets pronounced the vowel /a/ with a vibration pickup-type microphone, the ability to shut noise out increased 5 to 9 dB when compared with a noise-canceling microphone. If the subjects put on earmuffs, the ability to shut noise out increased 6–10 dB. According to the results of Experiment 2, the response decreased in the high frequency beyond 1 kHz. This might be caused by the dumping of bone conduction, We then tried to make an equalizer in order to produce a more natural voice by revising the high-range dumping.