Critical bandwidth widening means only low harmonics are resolved individually

Evidence

A psychoacoustic description of timbre perception must be based on the nature of the critical bandwidth variation with frequency, since this describes the nature of the spectral analysis carried out by the hearing system. The variation in critical bandwidth is such that it becomes wider with increasing frequency, and the general conclusion was drawn in the section on pitch perception in Chapter 3 (Section 3.2) that no harmonic above about the fifth to seventh is resolved no matter the value of f0. Harmonics below the fifth to seventh are therefore resolved separately by the hearing system (e.g., see Figure 3.11), which suggests that these harmonics might play a distinct and individual role in timbre perception. Harmonics above the fifth or seventh, on the other hand, which are not separately isolated by the hearing system, are not likely to have such a strong individual effect on timbre perception, but could affect it as groups that lie within a particular critical band. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1473

Categorization

• DEFINE: Explains critical bandwidth as the mechanism of the hearing system’s spectral analysis and why it widens with frequency.
• XREF: Directly ties back to the book’s earlier pitch-perception chapter (Section 3.2, Figure 3.11) — worth linking to my notes on harmonic resolution and pitch. — connects to: Harmonics are unresolved when critical bandwidth exceeds harmonic spacing. — David Howard, Jamie Angus, coustics and Psychoacoustics, 883; Only harmonics separated by more than the ear’s critical bandwidth are resolved; A filter resolves a harmonic it is centered on even when bandwidth exceeds spacing — David Howard, Jamie Angus, coustics and Psychoacoustics, 884 (+4 more)

Broader Connections

• Harmonics are unresolved when critical bandwidth exceeds harmonic spacing. #contradicts (1.00) — David Howard, Jamie Angus, coustics and Psychoacoustics, 883
• Only harmonics separated by more than the ear’s critical bandwidth are resolved #expands (1.00)
• Unresolved harmonics smear together as frequency rises #expands (1.00)
• Only low-numbered harmonics are resolved, higher ones blur together in the internal representation #corroborates (1.00) — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 509
• Harmonics cease being resolved when their spacing falls below the ERB #corroborates (1.00) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1505
• A filter resolves a harmonic it is centered on even when bandwidth exceeds spacing #complicates (0.80) — David Howard, Jamie Angus, coustics and Psychoacoustics, 884