Residential Broadband, Second Edition

The Limits of Audio/Visual Perception

While there are limits to what networks can deliver economically, there are also limits to what humans can perceive. Human perception is not infinitely sensitive, so some coarseness of data can be accepted, which tends to make life easier for the network developer.

For example, the limit of human auditory sensitivity is in the range of 20 Hz to 20 kHz per second. So there is no point in a network providing audio service above that pitch.

Television in the United States is shown at 30 frames per second. Generally, there is no need to show at higher rates because viewers can't tell the difference anyway. One exception where humans can tell a difference is for flashing lights. Flashing lights at 30 frames ...