Human hearing focuses on the first 20 to 30 decibels of reverberant decay

Evidence

Because we rarely hear a full reverberant decay, our ears and brains have adapted, quite logically, to focus on what can be heard. Thus we are more sensitive to the effects of the first 20 to 30 dB of the reverberant decay curve. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1925

Categorization

• XREF: Connects to the broader psychoacoustics theme of hearing adapting to environmental constraints — links to earlier chapters on how the ear-brain system tunes to what is audible.
• DEFINE: Explains why EDT rather than raw T60 matters perceptually.