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Department of Electrical Engineering - Columbia University

SPEECH AND AUDIO PROCESSING AND RECOGNITION

ELEN E6820 - Spring 2001

Sound examples

This page contains some sound examples that have been presented in class. Note that many of the sound examples from the later lectures are in the lecture notes directory, and are actually linked in to the PDF files containing the lecture slides, which you can access via the course outline page.

2001-02-22

Here are the sound examples from the ASA/IPO Auditory Demonstrations CD that I played or tried to play in the auditory perception class:

• Critical bands by loudness comparison, the demonstration of the basic effect from the Zwicker paper.
• Pitch streaming, where the perceived 'rhythm' changes as the tones get close together.
• Pulsation threshold, where the tone interrupted by noise begins to sound continuous as the noise becomes a plausible masker.

I'm sorry that these examples are rather big, but it's very risky to use advanced audio compression on psychoacoustic examples!
Here are the other sound examples from the lecture too:

• Clean "football team coach" utterance
• "football team coach" with noise burst obscuring a phoneme (my attempt at a 'phonemic restoration' example)
• Original of sinewave speech example (That's actually Prof. Remez speaking. I got the example from the Haskin's site)
• Sinewave replica of above

2001-01-23

Some examples of time scale modification:

• Here is the unprocessed original female speech
• Here it is stretched by a factor of two using SOLAFS (here is the matlab code for SOLAFS). Notice how the vowels are stretched very nicely (where finding alignment points is easy), but the consonants get messed up.
• Here it is streched by a factor of two using the phase vocoder (and here is matlab code for the phase vocoder). It sounds a lot smoother, though maybe a little unnatural.

Here is the Matlab diary of generating these examples.