Direct sound preserves signal information because it has not yet hit any boundary.

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 Figure 6. — David Howard, Jamie Angus, coustics and Psychoacoustics, 1729

Categorization

Category: Causal Relationships

• DEFINE: Defines why the direct-sound component matters: only it carries the waveform uncontaminated.

Related

• The direct sound carries speech clarity, unlike reflected sound. (similarity 0.94)
• Direct sound carries signal information uncontaminated and governs speech intelligibility (similarity 0.84)
• The optimum direct-to-reflected sound ratio rises from speech to music (similarity 0.84)
• Direct sound intensity falls with the square of distance from the source (similarity 0.83)
• Speech intelligibility depends on high direct-to-reverberant sound ratios (similarity 0.82)
• Distance from a source changes the balance between direct and reverberant sound (similarity 0.82)
• Every 1 dB of signal-to-noise improvement raises speech intelligibility by 7 to 19 percent (similarity 0.81)
• The first-arriving direct sound perceptually dominates despite carrying less energy (similarity 0.81)
• Direct sound determines localization, loudness, and perceived spectrum quality (similarity 0.80)
• Speech comprehension depends on direct sound, which falls off with the inverse square law. (similarity 0.80)
• Sound power, unlike intensity, is direction-independent and context-free (similarity 0.79)
• A critical distance exists where reverberant sound begins to dominate the direct field (similarity 0.79)
• Listener perception depends on sound power, direct sound, and reflections by frequency band (similarity 0.79)
• Large path-length variation causes poor direct-to-reverberant ratio and feedback (similarity 0.79)
• Non-environment rooms suppress all but direct sound for clearer audio detail and imaging (similarity 0.78)