How Sound Localization Works

Interaural level differences (ILDs)

Difference in sound pressure level reaching each ear

Physiology of binaural processing

Processing of binaural cues in the superior olive

Lateral superior olive (LSO)

Part of the superior olive that processes ILDs

Strengths and weaknesses of binaural cues

Advantages and limitations of ITDs and ILDs

Cone of confusion

Set of points with identical ITDs and ILDs

Relative intensity

Sound amplitude decreases with distance

Reverberation

Reflection of sound off objects, providing distance cue

Sound localization

Determining the location of a sound in space

Monoaural cues

Cues that help localize sound using one ear

Pinna

Outer ear structure that filters sound

Intensity and reverberation

Factors that aid in sound localization

Binaural cues

Cues that compare signals in both ears to locate sound

Interaural time differences (ITDs)

Time difference between sound arrival at each ear

Medial superior olive (MSO)

Part of the superior olive that processes ITDs

Elevation

Localization of sound source's height

Distance

Localization of sound source's proximity

Precedence effect

Localization of sound based on the first sound's direction

Auditory scene analysis

Process of segregating and grouping sound sources

Spectral grouping

Combining frequency components from the same source

Harmonicity

Frequency components that match are grouped together

Common frequency change

Frequency components that change together group together

Sequential grouping

Organizing sounds over time into separate events

Auditory stream segregation

Process of perceiving separate sound events

Similarity of pitch

Sounds with similar pitch often come from the same source

Temporal proximity

Sounds occurring in rapid succession are from the same source

Similarity of timbre

Distinct timbre indicates separate sound sources

Continuity

Sounds that stay constant or change smoothly come from the same source

Phonemic restoration

Perception of continuous sound interrupted by noise