Room response at a listener can be predicted from geometric reflection analysis

Evidence

Figure 2.6 shows my first attempt, in 1985, at making sense of the complicated loudspeaker/room system. The idea was to use the NRCC listening room as the example room and try to predict the sounds arriving at a listener. A geometrical analysis of a loudspeaker and listener placed in that room identified the off-axis angles associated with floor, ceiling and side wall reflections and the path lengths to the listener. Perfect specular reflection was assumed at the reflection points, and the inverse-square law was used to calculate the propagation attenuation for each reflected sound. — Toole, Floyd E, Sound reproduction- the acoustics and…, 181

Categorization

Category: Craft and Method

• XREF: The method of predicting listener arrival from first-reflection geometry plus power summation presages later modeling approaches in audio DSP and ray-tracing acoustics.

Related

• Room acoustics requires modeling direct sound then early reflections (similarity 0.88)
• Sound power predicts room response for omnidirectional speakers while directivity shapes room curves (similarity 0.83)
• Room boundary reflections are the second loudest sounds a listener hears (similarity 0.82)
• Early reflections boost perceived loudness while loud late reverberation degrades intelligibility (similarity 0.82)
• Horizontal and vertical reflections dominate because they are the strongest first reflections. (similarity 0.81)
• Room boundaries alter loudspeaker output through reflected image sources (similarity 0.81)
• Loudspeaker directivity determines which curve predicts the room (similarity 0.81)
• Room intelligibility can be predicted from impulse response and noise levels (similarity 0.81)
• Early room reflections benefit speech intelligibility as much as raised direct sound level (similarity 0.81)
• Listener perception depends on sound power, direct sound, and reflections by frequency band (similarity 0.81)
• On-axis response alone cannot predict how a loudspeaker sounds in a room (similarity 0.81)
• Loudspeakers and rooms act as a combined system that cannot be judged separately (similarity 0.80)
• Loudspeaker off-axis response dominates in-room energy at the listening position. (similarity 0.80)
• A single recorded click can predict any sound’s behavior in a space (similarity 0.80)
• Human listeners can identify loudspeaker qualities through rooms, while microphones cannot. (similarity 0.80)

Broader Connections

• Room intelligibility can be predicted from impulse response and noise levels #corroborates (0.85) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 2415