Chapter 10: Auditory Scene Analysis Flashcards
(14 cards)
Auditory field is all around: Azimuth v. Elevation
Azimuth: left/right
Elevation: up/down
Binaural cues
One sound entering both ears
-Two ears critical for localization of a source
Interaural Time Difference (ITD)
Difference in time between a sound arriving at each ear
-Affected by frequency
-Brain measures time it takes for traveling waves in the cochlea to move from high to low frequency parts of the basilar membrane
Interaural Level Difference (ILD)
-Difference in intensity between a sound arriving at each ear
-Head creates a sound shadow
Cone of the confusion
-Area to the left and right where sounds produce identical ITD and ILDS
Duplex Theory
-Low Frequencies rely on ITD
-High Frequencies rely on ILD
Directional Transfer Function
-Pinna, ear canal, head, etc. change intensity of sounds with different frequencies that arrive at each ear from different locations in space
-Unique to everyone
Judging Distance
-Decrease in intensity follows inverse square law
-Relative intensity is useless
-Doubling distance subtracts 6dB
Spectral Composition
Cue to distance judgement
Relative Amounts of
-Direct v. Reverberant Sound
-High v. low frequencies
Complex Sounds
-Enviornmental sounds are generally complex
-Musical Notes have a fundamental frequency
-Harmonic spectrum gives a note its richness
Timber
-Tone Richness
–Affected by harmonic spectrum
–Affected by attack (explosive energy at onset)
–Affected by decay (decrease in energy over time)
Listeners can judge two sounds with the same loudness and pitch as different
Auditory Scene Analysis
Evaluating the auditory scene with multiple sound sources
Auditory Stream Segregation
-Separation of sounds into different sources or events
Gestalt Principles of auditory grouping
-Grouping by Onset
-Grouping by Timber
–Notes of similar sound qualities are grouped as one source
-Grouping by pitch
–High notes v. low notes being grouped
-Principle of continuity is the auditory system filling in holes with continuous sounds
