Sound demos

The demos in this library assume that a program called ptplay is in your path, and that it accepts data of an appropriate format and will play it over the computer sound card at an 8 kHz sample rate.

The samples are written into a file before they are played. Since a large number of samples must be generated, these demos can take some time to run.

chirpplay
Chirp generator.
fmplay
Sound generator using FM modulation.
speech
Read a speech signal from a file, and encode it at two bits per sample using adaptive differential pulse code modulation with a feedback-around-quantizer structure. The signal is then reconstructed from the quantized data. The original and reconstructed speech are played.
KSchord
Simulation of plucked string sounds using the Karplus-Strong algorithm.
vox
Coarticulation with an Adaptive Vocoder. The resulting FM synthesized sound is played.
blockVox
A block processed version of the vox demo.
LossySpeech
Illustrate the effect on speech of a zero-substitution policy in a network with 48 byte packets and a variable loss probability.
LossySpeechPrevCell

Illustrate the effect on speech of a previous cell substitution policy in a network with 48 byte packets and a variable loss probability.
perfectReconstuction

Eight-channel perfect reconstruction one-dimensional analysis/synthesis filter bank. The incoming speech signal is split into eight adjacent frequency bins and then reconstructed. The original and reconstructed speech are played.
subbandcoding
Four channel subband speech coding with APCM at 16kps.