~Chapter 12 - Lecture Section 12.1 Flashcards
What is Auditory Space?
We are able to perceive objects and events located at specific positions in space based on sound alone.
Auditory Space is talking about the stimulus, the info about object location that is available
What is Auditory Localization?
We can localize an object’s position in space based on sound.
Auditory Localization is the perceptual ability for us to take advantage of the info of Auditory Space.
Auditory Localization is often described in coordinates in ___ dimensions
3
What are the 3 coordinates used to describe Auditory Localization?
Azimuth, Elevation, and Distance
Azimuth is the ___ meridian, such as ___ and ___.
horizontal // left // right
Elevation is the ___ meridian, such as ___ and ___.
vertical // up // down
There are not auditory mechanisms to determine ___.
distance
Azimuth and Elevation are usually reported in ___ to account for ___.
degrees // absolute Distance
Are people generally good or bad at localizing sounds?
People are pretty good at localizing sounds
When subjects were blindfolded and asked to identify sounds coming from inside the dome, researchers found that people are most accurate for detecting the location of sounds ___, with an error of ___ degrees.
directly in front of them // 2-3.5
When subjects were blindfolded and asked to identify sounds coming from inside the dome, researchers found that people are least accurate for detecting the location of sounds ___, with an error of ___ degrees.
around the side, above, and behind the head // 20
The Primary receptor for sound (the Cochlea) detects ___ and ___ of sounds, not ___.
frequencies // intensity // space
The Auditory system uses ___, similar to the visual system using ___.
Location Cues // Depth cues
What are Binaural Cues?
Cues that require two ears
What are Monaural Cues?
Cues that require only one ear
Monaural Cues include the ___ and ___.
Head // Pinnae
Binaural Cues use ___ and ___.
Interaural Time Difference (ITD) // Interaural Level Difference (ILD)
What is the speed of sound?
340m/s
What does ITD rely on?
ITD relies on the fact that the Speed of sound 340m/s is pretty slow in terms of how fast the nervous system operates.
When sound is coming from the front, sound waves arrive to the Left and Right ears at ___ time(s), and the ITD = ___.
the same // 0
When sound is played from the side, sound travels ___ enough that there is ___ from when sound arrives at the near ear to when it activates the far ear, the ITD = ___.
slow // a detectable difference // > 0 (greater than 0)
ITD is really intuitive if you consider ___.
Aperiodic sounds
What does it mean when the Tympanic Membranes are moving out of phase?
One is being pushed in and the other is being pushed out
The Tympanic Membrane is pushed in when it’s struck by ___.
Condensation
The Tympanic Membrane is pulled out when it overlays a ___.
Refraction
When sounds are being played from the side and the wavelengths are correct, there will be times when the Tympanic Membranes are moving ___.
Out of phase
What does it mean when the Tympanic Membranes are moving in phase?
If a continuous Periodic Sound Pure Tone is being played from the front, both eardrums would be pushed in or pulled out at the same time.
For continuous sounds, Interaural Time Difference could better be described as ___.
Interaural Phase Difference
The ITD can only detect Phase Differences for relatively ___ wavelengths (___Hz), because the wavelength has to be ___ enough such that when one eardrum is pushed in, the other is pulled out. If the wavelength is too ___, there can be a lot of ___ info because there could be many wavelengths between the ears.
long // low frequencies ~20 – 1000 // long // short // lost
When sound played from the side, our head creates a barrier that ___ the intensity of sounds that reach the ___ ear, the head casts an ___.
reduces // far // Acoustic Shadow
For high-frequency information, the sound will be ___ for the ___ ear in an unobstructed path.
louder // near
For the far ear, it will be ___ because some of that sound energy is being ___ by the head.
quieter // absorbed
Sound waves will bounce off of ___ objects, but they will pass around ___ objects.
large // small
The ILD cue is only available when the wavelength of the sound is ___ than the width of the head, around ___Hz.
smaller // 1000 – 20,000
For short wavelengths, due to a ___ coming from the side, there is a nice Acoustic Shadow being cast, this will lead to a ___ ILD.
high frequency // strong
For ___ with a long wavelength coming from the side, there is no ___ cast and there will be the same ___ reaching the Near ear vs the Far ear.
lower frequencies // Acoustic Shadow // intensity
If sound is coming directly from the front, it will strike both ears with ___ intensity because no ___ is protecting any of the ears.
equal // Acoustic Shadow
Which cues are used to judge Azimuth?
Both Interaural Time Difference and Interaural Level Difference are used to judge Azimuth
Interaural Time Difference and Interaural Level Difference have ___.
complimentary Frequency Requirements
The Interaural Time Difference affects Azimuth judgments only for ___ stimuli, around ___Hz. This is because sound frequencies that are too high can create errors if there are many wavelengths between the near ear and the far ear.
low-frequency // 20-1000
Interaural Level Difference affects Azimuth judgments only for ___ stimuli around ___Hz.
high-frequency // 1,000-20,000