Final: Chapter 12 Flashcards
the ability to tell the direction from which a sound is originating.
Sound localization
a psychoacoustic phenomenon that describes how the brain perceives sound when multiple sounds reach the ear close together in time
Precedence effect
The ability to separate each of the sound sources and separate them in space is achieved
Auditory stream analysis
the process of determining which regions and parts of the visual scene belong together as parts of higher order perceptual units such as objects or patterns
Perceptual grouping
the way that auditory events are localized, or how a person perceives an auditory scene in space
Auditory space
locating of sound sources in the auditory space
Auditory localization
What is the activation of nerve fibers in the cochlea based on?
on the tones’ frequency components and not on where the tones are coming from
TRUE OR FALSE: 2 tones with the same frequency that originate in the different locations will NOT activate the same hair cells and nerve fibers in the cochlea.
FALSE, they will activate the same hair cells and nerve fibers
are created by the way sound interacts with the listener’s head and ears
Location cues
What are the 2 kinds of location cues?
Binaural and spectral cues
Location cue that depends on both ears
Binaural cues
Location cue that depends on one ear
Spectral cues
extending from left to right
Azimuth
extending up and down
Elevation
What three dimensions to locate the position of a sound are location cues used for?
- azimuth
- elevation
- distance of sound source from the listener
Based on the difference in the sound pressure level of the sound reaching the two ears
Interaural Level Difference (ILD)
reduces the intensity of sounds that reach the far ear
Acoustic shadow
What type of sound does Interaural Level Difference work best at?
high frequency sounds
The time difference between when a sound reaches the left ear and when it reaches the right ear.
Interaural Time Difference (ITD)
If the sound source is directly in front of the listener, what is the ITD? why?
The ITD is 0 because the distance to each ear is the same: the sound reaches the left and right ears simultaneously
When does ITD become larger?
When sound sources are located more to the side
ITD is most effective for determining the locations of what kind of sounds?
low frequency sounds
Cues in which information for localization is contained in differences in the distribution (or spectrum) of frequencies that reach each ear from difference locations
Spectral cues
ILDs and ITDs work for judging _________ location.
azimuth
What do spectral cues work best for?
judging elevation, especially for spectra extending to higher frequencies
Proposes that neurons are wired so they each receive signals from the two ears/ proposes a circuit that contains a series of ITD detectors, each tuned to respond best to a specific ITD
Jeffress Model of auditory localization
They only fire when both signals coincide by arriving at the neuron simultaneously/ each one fires best to a particular ITD
Coincidence detectors/ ITD dectectors
ITD is indicated by the place (which neuron) where the activity occurs
place code
Plots the neuron’s firing rate against the ITD
ITD tuning curves
What does the broadness of the ITD curves in mammals mean?
that coding for localization is based on broadly tuned neurons
What is binaural localization based on for birds?
sharply tuned neurons
What is binaural localization based on for mammals?
broadly tuned neurons
Why is the code for birds a place code?
Because ITD is indicated by the firing of neurons at a specific place in the nervous system