A mathematical function is periodic if f(x) = f(x+nT) where n is an integer and T is constant unit of time. Sounds that we hear as pitch are all periodic. A pitched sound wave has regulary spaced patterns of compressed and rarified air molecules. Granted these pressure changes are very small, but when they strike the eardrum, the eardrum moves in and out at the frequency of the pressure changes. The motion of the eardrum sets fluid in motion that tickles tiny hair cells in the inner ear that in turn send electrical signals to the brain.
Assume the audio CD sampling rate 44100 and a duration of about a second.
We'll answer these questions and more in Lab 2 today.
1. What does a waveform sound like if every sample is 0?
2. What does a waveform sound like if every sample is 1?
3. What does a waveform sound like if every sample is random?
4. What does a waveform sound like when every 100th sample is a 1 and all others are zero?
5. What does a waveform sound like when the first 50 samples are 1 and the second 50 are 0?
6. What does a waveform sound like if every 100 samples rise uniformly in amplitude from 0 to 1?