Topic 10- Hearing in the environment Flashcards
What is auditory space ?
Perception of where sounds are located in space
What is auditory localization?
The process of locating sound sources within auditory space
Auditory system must use information other than what’s happening in the cochlea to determine location.
What am I?
Location cues
What are binaural cues?
Use information reaching both ears to determine azimuth of sounds
What are two types of binaural cues?
- Interneural level difference (ILD)
- Interneural time difference (ITD)
If an object is BLANK than the space between the waves, a BLANK is produced.
If an object is BLANK than the space between the waves, a BLANK is not produced.
- larger, shadow
- smaller, shadow
What is the binaural cue ILD?
2pts
- Based on the difference in the in the sound pressure level between the left and right ears
- Occurs because the head acts as a barrier that creates an acoustic sound shadow, reducing the intensity of the sound that reach the far ear
BLANK objects: create noticeable differences in sound intensity between your ears, making it easier to locate the sound source.
BLANK objects: have less impact on sound waves, making it harder to determine the sound’s location.
- large
- small
What type of frequency sounds is ILD an effective cue for locating?
- high frequency sounds not low frequency sounds
What is the binaural cue- Interneural time difference (ITD)?
The time difference between when a sound reaches the left and right ears
ITD-
If the source is located directly in front, the arrival times are …
If a sound is located to the side, the sound will reach…
- the same
- one ear before the other
When does the ITD increase? When is it useful for?
2pts
- Increases as the sound sources are located more and more to the side
- useful for low frequency sounds
Locations in space in which the sound sources all have the same ITD and ILD, so their location is ambiguous
Cone of confusion
What are spectral cues? What is an example?
- The pattern of the distribution of frequencies reaching the ear that can help with locating a sound
Ex- elevation
The auditory system receives … from the pinna based on whether its coming from above, or below.
fill in the “…”
different patterns of sounds
What is Jeffress model of auditory localization
2pts
- Proposes that cells in the auditory system are wired to each receive signals from the two ears
- Depending on the sounds location, these two signals will meet somewhere in the circuit and cause a neuron to fire, indicating the sounds location
- Time difference between signals reaching the two ears.
- This time difference helps determine the direction of the sound source.
The farther a BLANK is from the center, the greater the distance to the sides it represents.
What am i?
coincidence detectors
What coincidence detectors indicate sounds come from the right and left?
- # 1/2/3/4 - indicate sound comes from the right
- # 6/7/8/9- indicate sound comes the left
What is the first place that receives signals from both the left and right ears?
The superior olivary complex
Lesioning this area causes people to have difficulties with localizing sounds.
What area is this?
The primary auditory cortex (A1)
What is the precedence effect? What happens if the time interval is too long?
2pts
When two similar sounds reach a listener’s ear separated by a time interval of less than approx 50ms, the listener only hears a single sound
If time interval is too long = lagging sounds are perceived as echoes
- The “sound environment”
- Includes the locations and qualities of all the different sounds that are present
- multiple sources of sound occurring all at the same time
What am I?
Auditory scene
What are the five steps in an auditory scene analysis?
- Location
- Onset synchrony
- timbre and pitch
- Auditory continuity
- Experience
Sounds that stay relatively constant are perceived as coming from the same sound source
a. onset synchrony
b. auditory continuity
c. timbre and pitch
b. auditory continuity
If two sounds start at different times, we are likely to perceive/organize them as different sounds.
a. onset synchrony
b. auditory continuity
c. timbre and pitch
a. onset synchrony
