A 30-40 ms delay separates fusion from echo in the precedence effect

Evidence

Some people have mistakenly taken this to mean that the delayed sound is masked—it isn’t. Within the precedence effect fusion interval, there is no masking; all of the reflected (delayed) sounds are audible, making their contributions to timbre and loudness, but the early reflections simply are not heard as spatially separate events. They are perceived as coming from the direction of the first sound—this, and only this, is the essence of the “fusion.” The widely held belief that there is a “Haas fusion zone,” approximately the first 20 ms after the direct sound, within which everything gets innocently combined, is simply untrue. — , Toole, Floyd E - Sound reproduction-…, 840 (#expands, via linked claim)

Categorization

• XREF: connects to: Complex high-Q objects multiply echoes while each weakens; Delays too short for echoes still audibly alter timbre through spectral combs; Precedence fusion suppresses spatial perception but never masks the delayed sound (+5 more)

Related

• Precedence fusion suppresses spatial perception but never masks the delayed sound (similarity 0.93)
• Late-arriving reflections within the fusion zone are audible but merge into one directional image (similarity 0.93)
• Precedence fusion is not masking; all reflections remain audible (similarity 0.90)
• The precedence effect suppresses spatial identity of reflections, not their audibility (similarity 0.90)
• Precedence accumulates source information while late arrivals actively disrupt perception (similarity 0.88)
• ETC spike heights correlate inversely with actual audibility of reflections (similarity 0.85)
• The precedence-effect fusion interval in real rooms far exceeds laboratory values (similarity 0.84)
• The 30 ms fusion limit applies only to equal-level speech in hemi-anechoic space (similarity 0.84)
• Two identical sounds within 30–40 ms are fused into one located auditory event. (similarity 0.83)
• Complex high-Q objects multiply echoes while each weakens (similarity 0.83)
• Precedence effect threshold curves hold stable across very different listening environments (similarity 0.82)
• Three distinct perceptual phenomena define the precedence effect. (similarity 0.82)
• Delayed identical sounds merge spatially until delays exceed 30-40 ms (similarity 0.82)
• The direct-to-reflection gap must stay under 30ms or become audible echoes. (similarity 0.81)
• Later-arriving reflections within the fusion zone do not create separate images. (similarity 0.81)

Broader Connections

• Precedence fusion suppresses spatial perception but never masks the delayed sound #expands (0.85)
• The precedence effect suppresses spatial identity of reflections, not their audibility #expands (0.80) — , Toole, Floyd E - Sound reproduction-…, 840
• Late-arriving reflections within the fusion zone are audible but merge into one directional image #expands (0.80)
• The precedence-effect fusion interval in real rooms far exceeds laboratory values #contradicts (0.75)