CSE 8A Chapter Notes - Chapter 8.1: Fast Fourier Transform, Sound, Frequency Domain
31 Oct 2016
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Reading assignment ch 8, intro to sound properties. The physics of sounds: sounds = waves of air pressure. Decreases in air pressure: wave shapes, frequency, and amplitude -> influences perception of sound. Distance from 0 point to greatest/ least pressure. Is the most important factor in our perception of volume: an increase in volume = increase in intensity. If amplitude doubles, intensity quadruples, and so on: frequency. How often a cycle (from greatest to least pressure) occurs. Exploring sounds: spectrum view in mediatools application generated by fourier transform. Sound from time domain (rises and falls in sound over time) into frequency domain (which frequencies are in sound, and energy of those frequencies, over time) Encoding sounds: digitizing sounds = turning sounds waves into numbers. 1) co(cid:373)puter"s hardware ha(cid:374)dles (cid:373)easuri(cid:374)g a(cid:373)ou(cid:374)t of air pressure against mic. Analog-to-digital conversion move from an analog signal (continuously changing sound wave) to a digital value.
