Sitting near walls creates frequency notches from delayed reflections

Evidence

Reflection and consequent delayed arrival of sound combined with direct sound produces preferred frequency bands separated by deep notches (see figures 23.27 and 23.28), in the repetition pitch scenario. This can impart a strong coloration, and is a good reason not to choose a concert seat too close to a wall. — Eric J. Heller, Why You Hear What You Hear- An…, 2443

Categorization

• XREF: The repetition pitch ‘notched frequency bands’ mechanism connects to earlier comb-filter interference from reflections.
• SEED: Practical advice angle: why concertgoers who sit near walls hear ‘colored,’ notched, inferior sound — a physics-based seating guide.