Perception 5- localisation & auditory scene analysis Flashcards
Localising sound- binaural cues
require comparison of signals in left and right ears
Vital for signalling in azimuth (left-right plane)
Localising sound- monaural cues
Work with one ear
Localise elevation and distance of sound
Interaural time differences (ITDs)
The relative time which a sound arrives at the two ears depending on its location in azimuth (left-right)
Depends on- speed of sound and difference between two ears
Interaural level differences (ILDs)
Relative sound pressure reaching the two ears depends on the location of the source
Variation in sound level caused by acoustic shadow
Where does binaural processing take place?
Superior olivary complex (superior olive) within the brainstem
The …. superior olive contains neurone sensitive to ILDs
Lateral (LSO)
The ….. superior olive contains neurone sensitive to ITDs
Medial (MSO)
ITDs work with …..-frequency sounds
low
ILDs work with ….-frequency sounds
high
Cone of confusion
Set of points which a sound source will produce identical ITDs and ILDs
Relative intensity of sound
Sound intensity (amplitude) decreases with distance
Reverberation
The way sound reflects off objects
Provides a cue for distance
Multiple reflections -> reverberation
Precedence effect
Similar sounds arriving in quick succession from different locations are localised according to the direction of the first sound
Examples of auditory grouping
Common fate, proximity, similarity, continuity
Spectral grouping of sound
Combining different frequency sound components that occur at the same time
Harmonicity- if a component is mistuned it will be heard as a separate sound
