Abstract: An insert assembly for mounting in a shower or bath comprises a retaining ring comprising an engaging structure and an integral retaining flange, and having a retaining ring opening having an internal surface with retaining ring threads; a drain plug comprising a connecting structure and an integral holding flange, and having a drain plug opening and drain plug threads which engage the retaining ring threads; and a shower or bath insert, a portion of the insert being sandwiched between the holding flange and the retaining flange. A drain assembly comprises a retaining ring, a drain plug and a base having a drain structure to which the retaining ring is secured. There is also provided a method of mounting an insert assembly in a shower or bath.

Abstract: An electronic circuit for automatically adjusting the sensitivity of a microphone in accordance with changes in ambient noise is disclosed. A signal is generated which is proportional to the magnitude of the ambient noise and is applied through a reverse biased diode to slowly charge a capacitor by means of leakage current. The capacitor is connected to a control input of a sensitivity control circuit connected between the microphone and a device. The sensitivity control circuit is responsive to the signal from the capacitor voltage signal for controlling the sensitivity of the microphone relative to the device. Because the capacitor is discharged at a rate which is much faster than the rate at which it is charged, the circuit sensitivity is raised more quickly in response to a decrease in the magnitude of the ambient noise than it is lowered in response to an increase in the magnitude of such noise. A similar circuit is disclosed for use with a microphone threshold circuit.

Abstract: An electronic circuit for automatically adjusting the volume of an audio program in accordance with changes in the magnitude of ambient noise is disclosed. A voltage signal is generated which is proportional to the magnitude of the ambient noise. The voltage signal is applied to the cathode of a diode. The anode of the diode is connected through a capacitor to ground potential. The anode of the diode is also connected to a variable resistance device, which controls the volume of the audio program in accordance with the voltage across the capacitor. When the magnitude of the ambient noise increases, the capacitor is slowly charged by the leakage current passing through the reversed biased diode. As a result, the volume of the audio program is slowly increased. When the magnitude of such noise decreases, the capacitor is rapidly discharged through the forward biased diode. Thus, the volume of the audio program is rapidly decreased.