Delayed identical sounds merge spatially until delays exceed 30-40 ms

Evidence

When τ is zero, the listener perceives a single sound event in front, and when τ is increased to about 1 ms, the single spatial auditory event migrates towards the lead sound event. The spatial perception remains the same until the onset of the echo threshold, which occurs for values of τ of about 30–40 ms, depending on the signal. Only after this threshold is crossed does the lag sound event create an additive, spatially separated auditory event. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1500

Categorization

• SHARE: Send to anyone who mixes audio or designs hearing aids: the 30-40 ms fusion window is the reason early reflections don’t smear localization.