Uncontaminated direct sound is required for clear speech intelligibility in rooms

Evidence

The direct component is important because it carries the information in the signal in an uncontaminated form. Therefore, a high level of direct sound is required for a clear sound and good intelligibility of speech. The direct sound also behaves in the same way as sound in free space, because it has not yet interacted with any boundaries. This means that we can use the equation for the intensity of a free space wave some distance from the source to calculate the intensity FIGURE 6. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1685

Categorization

• XREF: Directly depends on the Chapter 1 free-space wave propagation and inverse-square intensity material. — connects to: Direct sound carries signal information uncontaminated and governs speech intelligibility — David Howard, Jamie Angus, coustics and Psychoacoustics, 1729; Speech intelligibility in rooms can be predicted from fluctuation strength — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 2059; Normal listening rooms improve rather than impair speech intelligibility — Toole, Floyd E, Sound reproduction- the acoustics and…, 560 (+6 more)

Broader Connections

• Direct sound carries signal information uncontaminated and governs speech intelligibility #corroborates (1.00) — David Howard, Jamie Angus, coustics and Psychoacoustics, 1729
• Speech intelligibility depends on high direct-to-reverberant sound ratios #corroborates (1.00) — David Howard, Jamie Angus, coustics and Psychoacoustics, 2434
• Intelligible speech design requires direct sound to exceed reverberant and noise. #corroborates (1.00) — David Howard, Jamie Angus, coustics and Psychoacoustics, 2478
• Non-environment listening rooms isolate direct sound to reveal low-level audio detail #exemplifies (0.95) — David Howard, Jamie Angus, coustics and Psychoacoustics, 2294
• Non-environment rooms suppress all but direct sound for clearer audio detail and imaging #exemplifies (0.95)
• Speech intelligibility in rooms can be predicted from fluctuation strength #qualifies (0.85) — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 2059
• Loudspeakers and rooms function together as a single audible system #qualifies (0.80)
• Early room reflections benefit speech intelligibility as much as raised direct sound level #complicates (0.75) — Toole, Floyd E, Sound reproduction- the acoustics and…, 557
• Normal listening rooms improve rather than impair speech intelligibility #contradicts (0.70) — Toole, Floyd E, Sound reproduction- the acoustics and…, 560