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Computational Auditory Scene Analysis. Kevin D. Donohue Databeam Professor Electrical and Computer Engineering University of Kentucky. Describe What You Hear. Scene 1. Scene 2. Scene 3. Sounds downloaded from http://www.prankcallsunlimited.com/. Auditory Scene Analysis.
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Computational Auditory Scene Analysis Kevin D. Donohue Databeam Professor Electrical and Computer EngineeringUniversity of Kentucky
Describe What You Hear Scene 1 Scene 2 Scene 3 Sounds downloaded from http://www.prankcallsunlimited.com/
Auditory Scene Analysis Auditory Scene Analysis (ASA) is a cognitive process that organizes sounds into perceptual objects. • Computational Auditory Scene Analysis (CASA) uses computational models to study ASA.
Auditory Scene: Input • Sensory organs (ears) separate acoustic energy into frequency bands and convert band energy into neural firings • The auditory cortex receives the neural responses and abstracts an auditory scene. http://hyperphysics.phy-astr.gsu.edu/hbase/sound/hearcon.html Time Frequency
High-Level Cognition Acoustic to Neural Conversion Organize into Auditory Streams Representation of Reality Auditory Scene: Perception • Perception derives a useful representation of reality from sensory input. • Auditory Stream refers to a perceptual unit associated with a single happening (A.S. Bregman, 1990) . Schema-driven/Top-downProcesses Primitive/Bottom-upProcesses
Auditory Stream Experiment Bergman & Campbell (1971) • Streams tend to form by grouping notes close in time and frequency (similarity and proximity). http://www.psych.mcgill.ca/labs/auditory/demo3.html http://www.psych.mcgill.ca/labs/auditory/demo2.html
Circularity in Pitch Judgement • Shepard’s Scale (1964) (Auditory Demonstrations CD, from the Acoustical Society of America)
Perceptual Organization Organization properties: • Belongingness – a sensory element belongs to an organization (or stream) of which is a part. • Exclusive allocation – a sensory element cannot belong to more than one organization at a time. • Bregman & Rudnicky (1975)
Perceptual Organization Organization properties: • Closure – perceived continuity, a tendency to close strong perceptual forms, response to missing evidence.
Sequential and Spectral Integration in Forming Streams • Sequential Integration • Grouping sensory elements over time or events at different times considered to be from the same source/object. • Spectral Integration • Fusing simultaneous sensory elements over frequency into one.
Timbre and Spectral Integration • The time envelope and harmonic structure give rise the timbre of the sound.
Timbre and Spectral Integration • Simultaneous tones grouped by timbre Same Note (A) 2 Notes (F and A)
Auditory Scene Organization • Primitive Stream Segregation • Inherent constraints in auditory scene analysis (perceptual organization demonstrated by infants/children) • Schema-based segregation • Learned constraints in auditory scene analysis (differences in perceptual organization resulting from training and culture) (A.S. Bregman, Auditory Scene Analysis, MIT Press 1990, pp. 1-45)
Cues Use for Grouping From THE AUDITORY ORGANIZATION OF SPEECHAND OTHER SOURCES IN LISTENERS AND COMPUTATIONAL MODELS, M. Cooke and D. P.W. Ellis, 1999