Perceptual frequency scales are quasi-logarithmic and straighten masking thresholds

Evidence

However, regardless of the psychoacoustic bit allocation algorithm, they all effectively convert the linear frequency scale of the discrete Fourier transform into a perceptually based frequency scale similar to the ERB scale shown in Figure 5.10. Most use the Bark scale, which is similar but is based on the earlier work of Zwicker. Both scales are quasi-logarithmic and convert simultaneous masking thresholds into approximately straight lines. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2677

Categorization

• DEFINE: Bark and ERB scales are the perceptual frequency axes underlying masking models; the earlier Zwicker work is the historical lineage.
• XREF: Connects to Figure 5.10’s ERB scale and Zwicker’s masking work elsewhere in the book.