Room reverberation erases the audibility of phase changes in signals.

Evidence

If the group delay introduced by a communication channel is not smooth with frequency, and has abrupt phase delay differences in adjacent frequencies, the above-mentioned rules no longer apply. One such typical response is reverberation, where, at frequencies over the critical frequency (see Section 2.4.4), the phase response behaves randomly. In practice, most of the phase-related effects are not audible at all in reverberant conditions. When a buzzy signal is filtered with such a random phase response, the buzzyness vanishes, and the firing rate spectrogram resembles the lower-right plot in Figure 11.11. If the phase delay is changed at one frequency in such a case, almost invariably, no audible changes are introduced. In other words, a phase-sensitive signal can be made phase-insensitive by adding the effect of room reverberation to it. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1281

Categorization

Category: Causal Relationships

• XREF: Connects to the earlier soundscape/noise work on how room acoustics shape perception; also relevant to why transient room treatment changes perceived sound quality.

Related

• Room reverberation can render phase-sensitive signals perceptually phase-insensitive (similarity 0.96)
• Room acoustics degrade phase-change sensitivity by roughly threefold (similarity 0.94)
• Room resonances, not amplifier phase response, govern audible phase distortion (similarity 0.92)
• Phase alignment creates a ‘buzzy’ timbre perceptible without room reflections (similarity 0.87)
• Noise and reverberation reduce modulation depth but preserve signal shape (similarity 0.86)
• Room reverberation suppresses the comb-filter colouring of amplitude panning (similarity 0.85)
• Room acoustics smear directional perception and mask recorded reverberation (similarity 0.84)
• Reverberation destroys the phase information that could encode meaning (similarity 0.84)
• Reverberant fields typically color perceived sound with excess bass that equalization must fix (similarity 0.84)
• Reverberation low-pass filters speech modulation while noise raises its floor (similarity 0.83)
• Room acoustical behavior changes across a broad transition region, not at one frequency (similarity 0.83)
• An audience’s breathing and perspiration dynamically alter a hall’s high-frequency acoustics (similarity 0.83)
• Room reverberation time varies with frequency, altering perceived timbre (similarity 0.83)
• A source’s changing directionality with frequency alters perceived timbre via the reverberant field (similarity 0.82)
• Reverberation masks consonant stops and blurs the formant transitions essential to speech (similarity 0.82)