Telephone handset for use in noisy locations

Claim 1

A telephone handset for use in noisy locations, comprising: a front housing and a back housing joined together; a tubular extension at one end of said front housing, the tubular extension extending forward from said front housing, and a receiver mounted in said tubular extension; means mounting a transmitter at the other end of said front housing, said means comprising a tubular support on said front housing and extending rearward thereof; a gasket resting on said tubular support and having an aperture therein; a holding member positioned on said gasket, said holding member including a tubular member; an annular gasket in said tubular member; said transmitter which comprises an electret transducer positioned in said tubular member on said annular gasket; said electret transducer enclosed in a housing open at a front end for admission of an acoustic input to the front of the transducer and having an opening at the rear for admission of an acoustic input from background noise to the rear of the transducer; an aperture in said front housing aligned with said tubular support to permit said admission of an acoustic input to the front end of the transducer; a grill in said back housing, aligned with said transmitter, and a dielectric shield positioned between said grill and said transmitter; a resister in series with the transmitter to reduce the transmit level; and a filter in front of the transducer to reduce the level of high frequency emphasis.