Room acoustics requires modeling direct sound then early reflections

Evidence

To meet the needs of computing and designing acoustics for complex spaces, a number of approximate numerical techniques have been developed. A conceptually simple technique is based on the image source method. Figure 2.24 illustrates a rectangular room with a source and a receiver. According to wave reflection laws, as illustrated in Figures 2.16 and 2.19, the reflections can be modelled as coming from image sources in image rooms. Each reflection in the real room corresponds to penetrating a wall between image rooms. Each path has an attenuation due to the 1/r distance law and damping for each reflection, and the wave will be delayed by the propagation time of the wave from the (image) source to the receiver. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 301 (#expands, via linked claim)

Because of the precedence effect, this reflection dominates, and the replayed sound is perceived as coming from a space the size of the listening room, which is clearly undesirable. What is required is a means of making the sound from the loudspeakers appear as if it is coming from a larger space by suppressing the early reflections from the nearby walls, as shown in Figure 7. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2283 (#corroborates, via linked claim)

Categorization

• XREF: connects to: Room response at a listener can be predicted from geometric reflection analysis; Room reflections can be modelled as sources in mirrored rooms — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 301; Early wall reflections pin perceived sound space to room size — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2283 (+8 more)

Broader Connections

• Room response at a listener can be predicted from geometric reflection analysis #corroborates (0.90)
• Room reflections can be modelled as sources in mirrored rooms #expands (0.90) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 301
• Early wall reflections pin perceived sound space to room size #corroborates (0.85) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2283
• Room boundaries alter loudspeaker output through reflected image sources #expands (0.80)