(compMus1) Audio Properties

For our purposes, we’re interested in a limited set of properties of audio, but we want to make sure that we distinguish between what is a physical property and what is a perceptual property, and what properties relate to one another.

Physical Properties (Acoustics)

1. Frequency
2. Amplitude
3. Spectrum

Perceptual Properties (Psychoacoustic)

1. Pitch (related to frequency)
2. Amplitude (loudness)
3. Timbre (spectrum)

Properties can change over time. We speak in terms of envelopes when this happens. An envelope is simply a function that changes over time. It can apply to any parameter.

Physical properties related to perceptual properties in a logarithmic (exponential) manner. For example, for every octave up in pitch, you double the frequency. So an octave is really 2-to-the-first power.