The audio signals presented here were recorded from various FM receivers and processed according to the patented noise reduction method. The method reduces any kind of interference of stereo signals or any combination thereof to mono quality without reducing the stereo separation.
Each WAV file contains the disturbed signal, followed by the improved signal.
Please download and convert the WAV files to mono if you need a mono version for comparison.
ACI (adjacent channel interference)
ACI + random RF noise
EMI (electromagnetic interference)
EMI 03 is a recording of an outdoor radio play. FM reception is disturbed by a blowdryer. The interference from the blowdryer mixes with the sound of croaking frogs.
As you can hear in the processed version, the frog sounds are clearly reproduced with full spatial information. In the background you can hear water splashing.
Both car radios and smartphones with built-in FM receivers reduce the stereo channel separation when the reception becomes poor to keep the audio SNR at a bearable level. An audio example with current car radios or smartphones can therefore unfortunately not demonstrate that the stereo channel separation can be maintained while at the same time improving the audio SNR.
Instead, the audio examples „mobile fast“ and „mobile slow“ were recorded with an FM receiver that does not reduce the stereo separation and does not change the audio signal when FM reception becomes poor.
In preparation: audio examples „mobile“
multipath01.WAV and multipath02.WAV were recorded in hilly terrain.
Please note that multipath interference also partly affects the sum signal (0-15 kHz). Since the noise reduction method cannot reduce interference beyond mono quality, some distortion can still be heard in these examples.