Raising a sound’s loudness shifts its perceived pitch except near 1-2 kHz.

Evidence

The loudness of sine wave signals, as a function of frequency and sound pressure levels, is given by the “phon” scale. The phon scale is a subjective scale of loudness based on the judgments of listeners to match the loud­ ness of tones to reference tones at 1 kHz. The curve for N phones inter­ sects 1 kHz at N dB(SPL) by definition, and it can be seen that the relative shape of the phon curves flattens out at higher sound levels, as shown in Figure 2.12. The relative loudness of different frequencies is not preserved, and therefore the perceived frequency balance of sound varies as the listen­ ing level is altered. This is an effect that we have all heard when the volume of a recording is turned down and the bass and treble components appear suppressed relative to the midrange frequencies, and the sound becomes “duller” and “thinner.” Ideally we should listen to reproduced sound at the level at which it was originally recorded. However, in most cases this would be antisocial, especially as much rock material is mixed at levels in excess of 100 dB(SPL)! — David Howard, Jamie Angus, coustics and Psychoacoustics, 617 (#expands, via linked claim)

Categorization

Category: Definitional Content

Related

• Volume changes alter perceived frequency balance, not just loudness (similarity 0.91)
• Pitch strength and loudness scale at sharply different rates with level changes. (similarity 0.88)
• Loudness depends on more than physical sound intensity alone (similarity 0.87)
• The phon unit measures perceived loudness, not physical sound level (similarity 0.87)
• Reduced playback levels cause timbral shifts and lost low bass (similarity 0.86)
• Loudness scales with frequency squared, requiring large amplitude at low frequencies (similarity 0.86)
• Small bass-level changes strongly alter perceived spectral balance (similarity 0.86)
• A 40 dB level increase shifts pure-tone pitch by at most about 3 percent (similarity 0.86)
• Turning down volume suppresses perceived bass and treble relative to midrange (similarity 0.86)
• Loudness slightly but measurably alters perceived pitch of tones (similarity 0.85)
• A ten-phon level reduction halves perceived loudness (similarity 0.85)
• Perceived pitch shifts measurably with loudness in frequency-dependent directions (similarity 0.85)
• Low-frequency loudness growth compresses as level rises (similarity 0.85)
• Loudness is a subjective percept standardized against 1-kHz tone levels in phons (similarity 0.85)
• Louder signals need disproportionately more dB to double perceived loudness (similarity 0.85)

Broader Connections

• Loudness changes shift perceived pitch; reverb conceals the effect musically #corroborates (0.95)
• Volume changes alter perceived frequency balance, not just loudness #expands (0.85) — David Howard, Jamie Angus, coustics and Psychoacoustics, 617
• Low-frequency tones become relatively louder as level increases. #corroborates (0.80)
• Pitch strength and loudness scale at sharply different rates with level changes. #corroborates (0.80)