Which combination of cues is most relevant for localizing high-frequency sounds?

• A. Interaural time differences and interaural intensity differences
• B. Interaural time differences only
• C. Spectral cues and interaural intensity differences
• D. Spectral cues only

Answer: (C)

High-frequency localization relies on two main cues: differences in sound level between the ears and the spectral shaping caused by the outer ear. As frequency is higher, the head creates a more pronounced shadow, making interaural intensity differences (ILD) a strong cue for where the sound is coming from in azimuth. At the same time, the pinna and ear canal sculpt the frequency spectrum in a direction-dependent way, producing spectral cues that help the brain resolve elevation and front‑back position. Interaural time differences become less reliable at high frequencies because the shorter wavelengths lead to rapid phase changes that are difficult to interpret consistently. Relying on spectral cues alone wouldn’t provide the binaural information needed for left-right localization, while ILD alone can miss vertical and front‑back distinctions that spectral cues help clarify. By combining spectral cues with interaural intensity differences, the auditory system has the most robust set of information for localizing high-frequency sounds.