The basilar membrane’s logarithmic spacing justifies plotting auditory representations on log frequency axes

Evidence

Figure 3–12 illustrates the spectrum (solid lines) and excitation pattern (dotted lines) for a synthetic vowel /i/ with a fundamental frequency of 150 Hz and an overall level of approximately 70 dB SPL. Notice the spectrum and excitation patterns are plotted on a logarithmic frequency axis; this is a common practice due to the logarithmic spacing of the basilar membrane. The spectrum in Figure 3–12 illustrates a robust representation of many of the 150-Hz harmonics — we see separate lines at least up to 2000 Hz. We also can see a robust presence of the formants: There are distinct spectral peaks around 300 Hz, 2200 Hz, and 3000 Hz. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 507

Categorization

• XREF: The log-spacing of the basilar membrane connects to place theory of pitch and classic cochlear tonotopy.