A super-compact microphone/receiver unit comprising a bone-conductive micro
phone and air-conductive microphone and a sound control method for mixing s
ounds from them according to the ambient noise level is proposed. The unit
makes telecommunication feasible in an environment 20 dBA noisier than the
noisiest one in which an ordinary air-conductive microphone can be used. Th
e units were supplied to The Organizing Committee for the XVIII Winter Game
s, Nagano 1998 (NAOC).