This filter project is a uniquely designed digital audio filter incorporating seven user selectable bandwidths combined with a digital noise reduction filter offering nine user selectable levels. The noise reduction filter is an adaptive filter, constantly sampling and storing the noise spectrum every 10 msec when no voice is present. The filter processes the received signal and differentiates noise from voice and attenuates the unwanted noise. The audio and noise reduction filters are controlled through two momentary switches and the status of each filter can be displayed by a combination of 4 LEDs. See “OPERATION” for details.
The MICRO dsPIC33FJ128MC804