What head-angle values were tested in the speech recognition study?

What head-angle values were tested in the speech recognition study?

• A. 0°, 20°, and 40°
• B. 0°, 15°, and 30°
• C. 20°, 40°, and 60°
• D. 0°, 30°, and 60°

Answer: (A)

How well someone can recognize speech depends on where the head is facing the sound source. Turning the head changes how each ear receives the signal, alters binaural cues, and modifies spectral filtering by the outer ear, all of which influence intelligibility. Using 0°, 20°, and 40° gives a clear, evenly spaced progression from directly toward the talker to a moderate turn away. This setup lets you see how recognition declines as the head angle increases while keeping changes gradual and interpretable. The baseline at 0° shows best or near-best performance, while 20° and 40° demonstrate the incremental impact of turning the head. Other angle sets either jump to more extreme orientations or use uneven steps, which can blur the trend and make it harder to interpret how small to moderate head turns affect speech recognition.

How well someone can recognize speech depends on where the head is facing the sound source. Turning the head changes how each ear receives the signal, alters binaural cues, and modifies spectral filtering by the outer ear, all of which influence intelligibility. Using 0°, 20°, and 40° gives a clear, evenly spaced progression from directly toward the talker to a moderate turn away. This setup lets you see how recognition declines as the head angle increases while keeping changes gradual and interpretable. The baseline at 0° shows best or near-best performance, while 20° and 40° demonstrate the incremental impact of turning the head. Other angle sets either jump to more extreme orientations or use uneven steps, which can blur the trend and make it harder to interpret how small to moderate head turns affect speech recognition.