Auditory Localization and Scene Perception

internal cues

Interaural time difference, Interaural level difference, Binaural, Informative about azimuth

spectral cues

filtering properties of the pinna, monoaural, mostly about elevation

reverberation and echoes

sound reflections, monoaural, informative about distance

Interaural time difference

difference between a sound arriving at one ear vs the other

Interaural level difference

difference in intensity between a sound arriving at one ear vs the other

Cone of confusion

positions in space where all sound produce similar ITDs and ILDs

Physiological basis

medial and lateral superior olive

Head-related transfer function

fold the pinna filter sounds differently depending on the direction (elevation) and frequency

Auditory grouping

pitch similarity, spatial proximity, common fate, good continuation

Echo

a discrete, clear reflection of sound heard by a listener

Reverberation

multiple, rapid sound reflection in a small or enclosed space that blend together

One cue to distance

the ratio of direct to reverberant sound energy

Helmholtz: perception as unconscious inference

We perceive most likely state of world given sensory data

Auditory stream segregation

perceptual organization of a complex acoustic signal to separate auditory events

Strategies for segregating sound sources

Spatial separation between sounds, Differences in sounds’ spectral or temporal qualities

Pitch similarity

Melody segregation by pitch similarity

Pitch Proximity

Segregation by proximity in SPACE

Common fate

Sounds that change together are grouped together

Good continuation

We tend to perceive discrete tones when tones are separated by silence, We perceive continuous tones when separated by noise (of similar intensity) an “occluder”