The direct sound carries speech clarity, unlike reflected sound.

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

• DEFINE: Explains why direct sound matters: it is uncontaminated by boundary interaction.

Related

• Direct sound preserves signal information because it has not yet hit any boundary. (similarity 0.94)
• The optimum direct-to-reflected sound ratio rises from speech to music (similarity 0.84)
• Direct sound carries signal information uncontaminated and governs speech intelligibility (similarity 0.83)
• 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 0.81)
• Inverse-square law governs direct sound intensity even inside enclosed spaces (similarity 0.80)
• Speech comprehension depends on direct sound, which falls off with the inverse square law. (similarity 0.80)
• Every 1 dB of signal-to-noise improvement raises speech intelligibility by 7 to 19 percent (similarity 0.79)
• Large path-length variation causes poor direct-to-reverberant ratio and feedback (similarity 0.79)
• Sound power, unlike intensity, is direction-independent and context-free (similarity 0.79)
• Distance from a source changes the balance between direct and reverberant sound (similarity 0.79)
• The first-arriving direct sound perceptually dominates despite carrying less energy (similarity 0.79)
• Listener perception depends on sound power, direct sound, and reflections by frequency band (similarity 0.79)
• Direct sound determines localization, loudness, and perceived spectrum quality (similarity 0.78)
• In rooms the inverse-square law applies only to the direct sound (similarity 0.78)