Heinrich's DNM Ambient Noise Sensor is designed to work with CNSM controller as part of the Ambient Noise Sensing System.

The sample and hold Ambient Noise Sensor system sets the volume of announcements just above the ambient noise, guaranteeing that announcements are always intelligible, and not excessively loud.

The DNM sensor detects ambient noise using its built-in microphone. The detected signal is weighted with a speech-band response for the best system performance and is then translated to a value of measured ambient noise in dBA. This value is used to proportionally adjust the system output gain for the configured output channel or channels.