Sound is converted into electricity by a telephone and then transmitted as an analog signal.
These waves have 3 fundamental characteristics:
- Amplitude, meaning the height (intensity) of the wave
- Frequency, which is the number of waves that pass in a single second and is measured in Hertz (cycles/second) (wavelength, the length of the wave from crest to crest, is related to frequency.).
- Phase is a third characteristic that describes the point in the wave’s cycle at which a wave begins and is measured in degrees. (For example, changing a wave’s cycle from crest to trough corresponds to a 180 degree phase shift).