Which two cues are used for horizontal sound localization?

Which two cues are used for horizontal sound localization?

• A. Interaural Time Difference and Interaural Loudness Difference.
• B. Interaural Time Difference and Interaural Phase Difference.
• C. Interaural Phase Difference and Interaural Frequency Difference.
• D. Interaural Time Difference and Interaural Level Difference.

Answer: (D)

Horizontal sound localization relies on two cues: the time difference of arrival at the two ears and the difference in sound level between the ears. The brain can detect when a sound reaches one ear slightly earlier than the other, which tells us about the direction to the source (interaural time difference). This timing cue is especially informative for low-frequency sounds, where wavelengths are long enough that the ears effectively sample the wave at different times. On the other hand, the head blocks or attenuates sound reaching the far ear more at higher frequencies, creating a noticeable level difference (interaural level difference). The brain uses this dip in loudness to infer azimuth for high-frequency sounds. Together, these two cues cover most of the horizontal plane. Interaural phase difference is related to timing at low frequencies but becomes unreliable at higher frequencies due to phase wrapping, and frequency differences between ears aren’t a standard cue for horizontal localization.

Horizontal sound localization relies on two cues: the time difference of arrival at the two ears and the difference in sound level between the ears. The brain can detect when a sound reaches one ear slightly earlier than the other, which tells us about the direction to the source (interaural time difference). This timing cue is especially informative for low-frequency sounds, where wavelengths are long enough that the ears effectively sample the wave at different times. On the other hand, the head blocks or attenuates sound reaching the far ear more at higher frequencies, creating a noticeable level difference (interaural level difference). The brain uses this dip in loudness to infer azimuth for high-frequency sounds. Together, these two cues cover most of the horizontal plane. Interaural phase difference is related to timing at low frequencies but becomes unreliable at higher frequencies due to phase wrapping, and frequency differences between ears aren’t a standard cue for horizontal localization.