Patent ID: 7333930

Claim:
A method for performing perceptual audio encoding on an input audio signal, the method comprising: (a) sampling the input audio signal to generate multiple sampled frames; (b) performing a first frequency transformation of each sampled frame into a frequency do main representation of the sample frame; (c) applying a magnitude compression operation to the frequency domain representation of each sampled frame to form a magnitude-compressed representation of the sample frame; (d) performing a second frequency transformation of the magnitude-compressed representation of each sampled frame to form a compressed spectral representation of the sample frame; (e) determining tonality of each sampled frame from a peak magnitude and an average magnitude of the compressed spectral representation of the sampled frame to distinguish tone-like components in the input audio signal from noise-like components in the input audio signal; (f) selecting a masked threshold for each sampled frame corresponding to the determined tonality of the sampled frame, wherein masked thresholds selected for the tone-like components in the input audio signal are different from masked thresholds selected for the noise-like components in the input audio signal; and (g) performing perceptual audio encoding on the sampled frames based on the selected masked thresholds to compress the tone-like features in the input audio signal at a different level of compression from the noise-like features in the input audio signal.