Microphone arrangement for noisy environment - uses motor-driven movement of microphone mouth mask during speech periods

摘要

In very noisy environments, the use of well-fitting mouth masks containing a microphone is known but constitutes an inconvenience. The appts. is arranged with a double microphone (DM) and adjacent mouth mask on a suspended arm (HB) which has a worm wheel (Z) pivoted at a point (DL2) above the microphone. The worm (Sch) is fitted to an axle (W) of a fractional horse power motor (M) which can be marginally turned around another pivot point (DL1). When the speech key (Ts) is despressed, a capacitor (C) discharges through a solenoid (HM) causing the worm gear to disengage from the wheel (Z) and permitting the tension spring (F2) to pull the mouth mask (Mk) against a stop (A2) and against the speaker's mouth. Due to the compensating action of the double microphone, it is not necessary to press the mouth mask very tightly onto the speaker's face. When the speech button is released, the motor is switched on to move the mouth mask away from the speaker and allowing him to breath freely.