Quelle Wikipedia:
Repairing a clipped signal
It is impossible to restore a clipped signal to its original state because part of the original signal was lost. It is preferable to avoid clipping, but if a recording has clipped, and cannot be re-recorded, repair is an option. The goal of repair is to make up a plausible replacement for the clipped part of the signal.
Several methods can partially restore a clipped signal. Once the clipped portion is known, one can attempt partial recovery. One such method is interpolation or extrapolation of known samples. While this approximation is rarely close to the original, the subjective quality may be improved.
Other methods may also be used. One of the methods in CuteStudio Declip, for example, works by copying the signal directly from one stereo channel to another, as it may be the case that only one channel is clipped.
Several software solutions of varying results and methods exist to counteract this problem: Sony Sound Forge, Adobe Audition, Nero Wave Editor, and a plugin in the Audacity LADSPA package come with clip restoration software. There is also a Nyquist plugin called Clipfix for Audacity.
