The invention comprises the retrieval of a quantized spectrum of audio-data, which had been compressed conforming to psychoacoustic principles. This spectrum can be identified with the aid of sorted (and logarithmized) differences of the magnitude of the amplitude. A problem to be solved by the invention is to find the basis of sensitive indicators for the degree of quantization of a spectrum. Theresult of this calculation shows for a quantized spectrum several small values at amplitudes of the same quantization level, and obvious spikes at positions, where the amplitudes have reached a higherlevel of quantization, while a non-quantized spectrum typically resembles noise.
Method and equipment for detecting the quantization of spectra