Lossy audio encoding drops completely masked components from transmission

Evidence

Using some form of simultaneous masking model masking curves, which are different for tonal and nontonal sounds, a signal-to-masking ratio (SMR) is calculated and the bits allocated such that components that need a high SMR are given more bits than those that have a lower SMR. For components that have a negative SMR, no bits are allocated because these components are masked and therefore need not be transmitted. The amount of bits that can be allocated depends on the desired bit rate. Also, the process interacts with itself, so this process usually is inside some form of optimization loop that minimizes the total perceptual error. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2678

Categorization

• DEFINE: Explains signal-to-masking ratio as the mechanism deciding whether a spectral component gets transmitted.