Noise-Canceling Microphone

The Noise-Canceling Microphone uses a sophisticated design to filter out background noise. It also filters out feedback commonly heard from paging systems. It is also known as Confidencer microphone. Unlike standard microphones which only have ports in the front, noise-canceling microphones have ports in the front and the rear. Since ambient noise enters the microphone from both ports, the same pressure is put on both sides of the diaphragm. Because the ambient noise doesn't make the diaphragm vibrate, the ambient noise isn't heard. Since speech is entering from only the front of the microphone, the diaphragm vibrates from only the speech which means the background noise isn't heard. With a noise cancelling handset, the caller must speak directly into the microphone.

The Noise-Canceling Microphone is available in Electret or Carbon-compatible versions.

Electret-compatible Specifications:
- Sensitivity at 1 kHz: -35 ± 4 dBV
- Impedance at 1 kHz: 1600 ohms ± 35% ohms
- Maximum Drain Current: 0.5 mA at 1.5 VDC
- Operating Voltage Range: 1.1 - 9 VDC
- Noise Cancellation: NLT 6 dB (300 Hz to 3.3 kHz)
Carbon-compatible Specifications:
- Sensitivity at 1 kHz: -24 ± 4 dBV
- Impedance at 1 kHz: 70 ohms ± 15 ohms
- DC Resistance: 135 ohms ± 25 ohms (at 20 mADC)
- Operating Current Range: 6.5 - 140 mADC
- Operating Voltage Range: 2.0 - 6.5 VDC
- Noise Cancellation: NLT 6 dB (300 Hz to 3.3 kHz)