Group delay affects perceived quality only when it varies with frequency

Evidence

A technical measure commonly used to describe the temporal-domain characteristics of a signal or a transfer function is the group delay τg(ω), defined in Equations (3.23a) and (3.23ab) on page 51. It is related to the delay of the components of the envelope (or modulation) of a signal. For example, the phase characteristics of a loudspeaker can be described by group delay. The mean value of the delay has no importance in one-way communication, such as listening to music records. However, if two-way communication is utilized, the group delay should be minimized to avoid latencies. If the group delay changes significantly with frequency, audible degradations of quality may occur. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1274

Categorization

• DEFINE: Defines group delay and the important distinction between constant delay (harmless one-way) and frequency-dependent delay (audible degradation).
• XREF: Directly useful for two-way communication latency engineering, matching the reader’s goal of acoustic communication applications. — connects to: Perceived delay arises from mismatched interaction speeds, not actual slowness — Hartmut Rosa, Social Acceleration: A New Theory of…, 277