You must have version 1.1.90 firmware or higher installed. Some additional notes: The audio is sent through the Aux path to the Windows Volume Control. So the level (and mute) controls in both the Aux and master Volume Control affect the demodulated audio level. The Audio Gain control (in the DPX Spectrum settings>Audio Demod tab) should be set to a low value for most signals to prevent overload. The Windows Sound Recorder can record the demodulated audio in a .wav file for later playback. Recording is through Aux, and playback through Wave controls. The Windows Volume Control and Sound Recorder are at Start>All Programs>Accessories>Entertainment. The Volume Control is also normally on the Windows Task Bar. For the FM broadcast band in North America, set the RX Bandwidth to at least 150 kHz (since the peak deviation transmitted specification is 75 kHz). If you set the RX Bandwidth to a larger value, you may hear distortion due to an attempt to demodulate several stations simultaneously. The span must be set to greater than 625 kHz (up to the 110 MHz maximum) for a 150 kHz RX Bandwidth. When the RX Bandwidth is set to the spec for a signal, you must be tuned exactly to the signal (within approximately 20% of the bandwidth) or you will hear distortion.