SpecAnaSyn
Spectral Analysis and Synthesis of Sounds
... for sound loading and saving allows to support many uncompressed sound file formats (WAV, AIFF, AU, headerless RAW, ...), and also OGG and FLAC, but MP3 isn't supported.
Available parameters include window type, size, and overlapping; sinusoid discarding; equalization; time strechting, frequency scaling and shifting; frequency and amplitude interpolation; normalization; dynamic range compression and expansion, etc.
It can be used to obtain new sounds, from existing sound files.