Initial time delay gaps of 8-20 ms are naturally achieved in most rooms

Evidence

The initial time delay gap in the listening should be as large as possible, but is clearly lim­ ited by the time it takes sound to get to the rear wall and back to the lis­ tener. Ideally this gap should be 20 ms but it should not be much greater or it will be perceived as an echo. In most practical rooms this require­ ment is automatically satisfied and initial time delay gaps in the range of 8 ms to 20 ms are achieved. — David Howard, Jamie Angus, coustics and Psychoacoustics, 2276

Categorization

Category: Factual Claims

• DEFINE: Defines what an initial time delay gap is and its ideal range.

Related

• Early reflections must arrive within 20 ms or they are perceived as echoes. (similarity 0.91)
• A 0–30 ms gap before first reflections cues spatial size while avoiding echoes (similarity 0.86)
• A delay gap under 20 milliseconds makes a hall feel intimate (similarity 0.85)
• The direct-to-reflection gap must stay under 30ms or become audible echoes. (similarity 0.82)
• True envelopment requires delays beyond 80 ms that rooms cannot supply (similarity 0.82)
• First reflections must arrive within 30 ms to avoid being heard as echoes (similarity 0.82)
• Sound is localized to the first arriving acoustic source despite delayed reinforcement (similarity 0.81)
• Controlled-reflection technique maximizes initial time-delay gap by suppressing early reflections (similarity 0.81)
• True envelopment needs reflections delayed beyond 80 ms, impossible in small rooms alone (similarity 0.80)
• Suppressing early reflections in one listening zone widens the perceived time-delay gap (similarity 0.80)
• In small rooms RT target 0.2-0.5 s; early reflections dominate mid-high frequencies (similarity 0.80)
• In small rooms reflections arrive early and never form a diffuse field (similarity 0.80)
• Early wall reflections pin perceived sound space to room size (similarity 0.79)
• Late-arriving room sound becomes omnidirectional and uniformly distributed (similarity 0.79)
• Envelopment in small rooms must come from recordings rather than natural reflections (similarity 0.79)

Broader Connections

• Initial time-delay gaps between 8 and 20 ms are perceptually optimal #corroborates (0.90) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2290
• Maximizing the initial time delay gap restores the original recorded acoustic space #qualifies (0.75) — David Howard, Jamie Angus, coustics and Psychoacoustics, 2272
• The sound arriving first dominates perceived direction beyond 673 microseconds of delay #complicates (0.75) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 741
• In small rooms RT target 0.2-0.5 s; early reflections dominate mid-high frequencies #expands (0.70) — Toole, Floyd E, Sound reproduction- the acoustics and…, 1448