30. organization of aud. scene Flashcards
Auditory scene def?
All the sound entering the ears during the current interval of time
Auditory scene analysis def?
- The process of extracting and GROUPING together frequencies
- separating frqs from specific sources from the mixture of all frqs from all sources in the auditory scene
Auditory stream def?
- An assortment of frequencies occurring over time
- all emitted by the SAME SOUND SOURCE (or related sources)
- seem to “go together”
Auditory stream segregation
The process of perceptual ORGANIZATION of the auditory scene into a set of distinct auditory streams
What are the 2 major categories of grouping?
- simultaneous grouping
- sequential grouping
Simultaneous grouping def? What are the 2 subdivisions??
- ways to group sounds that occur simultaneously
- based on a short, given interval of time
- harmonic coherence
- synchrony (or asynchrony)
Harmonic coherence def?
- all multiples of a fundamental frq are perceived as a single auditory stream
- if one of the harmonics is changed to a NON-harmonic tone, it is perceived as a DIFF. auditory stream
Synchrony (or asynchrony) def? Example with harmonics?
Which visual grouping principle is it similar to?
- frqs with synchronous onset, changes, and offsets are perceived as a single auditory stream
- if harmonics 1,3,5 start/end before harmonics 2,4, they will be perceived as DIFF auditory streams, even while they’re overlapping
- if frqs have sync. onset, but some change and others don’t, they’ll be perceived as diff streams as well
- similar to the visual principle of COMMON FATE / common motion
Sequential grouping def? What are the 2 subdivisions?
- ways to group sounds that occur at different times (rather than simultaneously)
- grouping sequentially, over a period of time (not an instant)
- frequency similarity
- temporal proximity
Frequency similarity def?
- group by frqs that are close / near to each other
Frequency similarity - 2 examples from class?
- single, galloping stream vs 2 diff streams
- flanker and captor tones
Explain the galloping stream example
- in both scenarios, the rhythm was the same. A & B are similar frqs, A & C are farther apart
- you perceive a single stream that is “galloping” when they’re close
–> ABA, ABA, ABA… - you perceive 2 streams when they’re far
–> CCC
AAAAAA
Explain the flanker and captor tones example
- determining the directional change of the isolated target tones is easy
- flanker tones are distractors, add transitions and makes it hard to identify target
- captor tones:
–> pattern of tones at same frq as flanker
–> “capture” the flanker
–> perceive as a single auditory stream - once again, the target tones are isolated (separate stream), so its much easier with captor tones
Temporal proximity def? Example?
- grouping is affected by how close the sounds are in time
- A is high frq, B is low frq. They’re played alternatingly
- if there’s a short time between them, you perceive 2 streams
- if there’s a longer time between sounds, you perceive 1 stream that alternates/warbles
Perceptual completion of occluded sounds def?
What visual principle is this similar to?
- auditory system assumes a sound that’s interrupted (but continues) as a single stream
- similar to principle of good continuation
–> and interpolation (perceive missing edges/surfaces as continuing)