Non-periodic continuous-spectrum sounds like fricatives can still evoke pitch sensations

Evidence

There are sounds which have non-harmonic spectra for which a pitch is perceived; these are exceptions to the second part of the general statement given earlier that “sounds whose acoustic pressure waveform is non-periodic are perceived as having no pitch.” For example, listen to examples of the “ss” in sea and the “sh” in shell (produce these yourself or ask someone else to) in terms of which one has the higher pitch. Most listeners will readily respond that “ss” has a higher pitch than “sh.” The spectrum of both sounds is continuous and an example for each is shown in Figure 3.9. Notice that the energy is biased more towards lower frequencies for the “sh” with a peak around 2.5 kHz, compared with the “ss” where the energy has a peak at about 5 kHz. — David Howard, Jamie Angus, coustics and Psychoacoustics, 900

Categorization

• DEFINE: Clarifies that pitch arises from spectral peaks (center of gravity of energy) even in noise-like continuous spectra, refining the ‘non-periodic means no pitch’ rule.
• CANDY: ‘ss’ vs ‘sh’ — which sounds higher — is a delightful dinner-conversation party trick backed by real acoustics.
• SEED: Angle: how fricative consonant spectra map onto perceived ‘brightness’ of vowels and consonants — the acoustics hiding inside everyday speech sounds.