Continuous noise is a common problem with recordings captured from a diversity of sources, for example from magnetic tape (cassettes, etc.), as well as from older gramophone records.
The truth of the matter
Trying to remove hiss, hum, rumble, and similar noise, can be likened to trying to remove the milk from a cup of tea or coffee. Often, the noise can be reduced without degrading the underlying audio to an unacceptable extent. Sometimes the result will sound exactly as if the noise were actually removed, sometimes an objectionable torrent of noise will be reduced to acceptable background noise. Listen to the samples (Capercaille, Ted Weems, Percy Grainger) to see what can be achieved in reducing hum and hiss using the software on this site.
Treatment methods
The two methods of treating broadband noise that are used by software on this site are:
• Frequency domain based – used by the DeNoise application for hiss and other general broadband noise problems.
• Non-linear filter and wavelet based – used by the DeNoiseLF application for the treatment of hum, rumble, and other low-frequency noise.
Further information
For more detailed information follow the links below. For download and license conditions and purchase, go to the software pages.