Overly loud speech masks its own higher frequencies and gets less intelligible

Evidence

More subtly, it is possible for speech that is produced at high levels to mask itself. That is, if the speech is too loud, then, notwithstanding the improvement in signal-to-noise ratio, the intelligibility is reduced, because the low-frequency components of the speech mask the high-frequency components due to the upward spread of masking. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2480

Categorization

• SEED: A counterintuitive nugget for an essay or explainer on why ‘louder is not clearer’ in sound design, public address in worship spaces, or even how over-shouting in conversation degrades message delivery.
• XREF: Connects to the reader’s broader listening practice: the upward spread of masking from Chapter 5 reaffirms why volume alone never buys clarity, relevant to silent-retreat and soundscape work.

Related

• Loud speech can mask its own high-frequency components via upward spread of masking (similarity 0.93)
• Masking noises that mimic speech’s rhythm disrupt intelligibility more than loudness predicts (similarity 0.86)
• Loud speech sounds can mask quieter ones within the same utterance for hearing-impaired listeners (similarity 0.86)
• A narrow noise band can mask signals multiple octaves away at high stimulus levels. (similarity 0.86)
• Loud bass masking spreads upward to cover the voice frequency range (similarity 0.84)
• Masking asymmetry grows as masker amplitude increases, favoring upward masking (similarity 0.84)
• Louder maskers increasingly mask high frequencies over low ones. (similarity 0.84)
• Higher-pitched voices resist masking by reverberation and noise in public spaces (similarity 0.83)
• Masking acts within critical bandwidths, leaving distant-frequency sounds unaffected (similarity 0.83)
• Masking shifts thresholds upward and may alter just-noticeable sound changes at all levels. (similarity 0.83)
• Loudness is not reducible to sound pressure level or signal power (similarity 0.82)
• Masking noise raises the loudness threshold and fades audible tones (similarity 0.82)
• Removing low-frequency masker energy improves speech intelligibility by 0.65 dB per dB (similarity 0.82)
• Low-frequency maskers mask high-frequency signals more than the reverse, and this worsens with intensity. (similarity 0.82)
• Loud bass masks sounds across much of the audible spectrum, including vocals. (similarity 0.82)