Computer Science 1033A/B Lecture Notes - Lecture 8: Compact Disc, Voice Over Ip, Sound Card

• School: Western University
• Department: Computer Science
• Course: Computer Science 1033A/B
• Professor: Laura Reid

Document Summary

Allow communication over the web (audio conferencing) Voice muscle vibrate and cause the air to move. Nyquist limit: must take at least 2 samples for every cycle of the wave (if you take less than two sample there will be a completely different sound) Sampling: onumber of samples per second is represented in hertz (hz) onumber of 1000 samples per second is represented in kilohertz (khz) For cd quality we need 44,100 samples per second (44. 1khz) Number of samples we take per second of audio or number of times per second the waveform is measured. Sample size: 2 bit sampling = 4 tones. Computers have a sound card which samples (sets the number of sample and quantizes) the sound wave from the microphone. Sound card has an analog to- digital converter (adc) for recording and a digital to - analog converter (dac) for playing audio. Operating system talks to the sound card t actually handle the recording and playback.