Question 1

The ____ is important for binaural localization because it is where signals from the left and right ears first meet.
A) medial geniculate nucleus
B) cochlear nucleus
C) inferior colliculus
D) superior olivary nucleus

Accepted Answer

The superior olivary nucleus is where signals from the left and right ears first meet and is important for binaural localization.

Question 2

Hofmann et al. had participants wear artificial pinnae for about three weeks. Which of the following was a result of their study?
A) Participants could not adapt to wearing the artificial pinnae.
B) Participants adapted in about 19 days, but then could not accurately localize sounds when they removed the artificial pinnae.
C) Participants adapted in about 19 days, and then could accurately localize sounds when they removed the artificial pinnae.
D) Participants could not localize sounds along the azimuth with the new pinnae, but could localize sounds along the elevation coordinate after 3 days of adapatation.

Accepted Answer

According to the study by Hofmann et al., participants adapted to wearing artificial pinnae in about 19 days, and then could accurately localize sounds when they removed the artificial pinnae. Therefore, the correct answer is C.

Question 3

The cue of interaural level difference is
A) not effective for low-frequency sound stimuli.
B) equally effective for high- and low-frequency sound stimuli.
C) not effective for high-frequency sound stimuli.
D) only effective for middle-frequency sound stimuli.

Accepted Answer

The cue of interaural level difference is not effective for low-frequency sound stimuli because low-frequency sounds have longer wavelengths that can diffract around the head, making it difficult to create significant level differences between the ears.

Question 4

The ______ is the dominant cue for locating low-frequency sounds along the azimuth.
A) ITD
B) ILD
C) Both ITD and ILD are equally effective.
D) HRTF only

Accepted Answer

ITD (interaural time difference) is the dominant cue for locating low-frequency sounds along the azimuth, as the time delay between the arrival of a sound wave at the two ears is largest for sounds arriving from the side. This difference in arrival time is used by the brain to determine the source of the sound in azimuth. ILD (interaural level difference), on the other hand, is more effective for locating high-frequency sounds. HRTF (head-related transfer function) also plays a role in sound localization, but it is not the dominant cue for low-frequency sounds along the azimuth.

Question 5

Interaural time difference detectors
A) have not been found in the monkey auditory cortex.
B) have been discovered in the monkey occipital cortex.
C) have been found in the monkey auditory cortex that responds best to specific delays.
D) have been found in the monkey auditory cortex, but do not differentially respond to different delays.

Accepted Answer

Interaural time difference detectors have been found in the monkey auditory cortex that responds best to specific delays.

Question 6

Recanzone (2000) examined localization in A1 and the auditory belt area in monkeys. Results indicated that
A) the belt area is not involved in localization.
B) A1 provides the most specific localization information.
C) localization coded the same throughout the auditory cortex.
D) the belt area provides more specific localization then A1.

Accepted Answer

Recanzone (2000) found that the auditory belt area in monkeys provides more specific localization information than the primary auditory cortex (A1), suggesting a hierarchical processing of spatial information in the auditory cortex.

Question 7

Which of the following is NOT a coordinate system for auditory localization?
A) elevation
B) depth
C) azimuth
D) time

Accepted Answer

Time is not a coordinate system for auditory localization; it is a factor that can influence localization but not a spatial coordinate like elevation, depth, or azimuth.

Question 8

From the auditory nerve, information is passed through a sequence of subcortical structures. Which of the following reflects the correct sequence?
A) medial geniculate nucleus, cochlear nucleus, superior olivary nucleus, inferior colliculus
B) cochlear nucleus, superior olivary nucleus, inferior colliculus, medial geniculate nucleus
C) superior olivary nucleus, medial geniculate nucleus, cochlear nucleus, inferior colliculus
D) medial geniculate nucleus, inferior colliculus, cochlear nucleus, superior olivary nucleus

Accepted Answer

The correct sequence is cochlear nucleus, superior olivary nucleus, inferior colliculus, and then medial geniculate nucleus. This sequence follows the ascending auditory pathway, in which information is relayed from the lower structures to higher structures until it reaches the auditory cortex.

Question 9

Spectral cues for auditory localization are provided by
A) the frequency of the sound wave.
B) the interaural level difference.
C) the head position and the pinnae.
D) the motion of the stimulus.

Accepted Answer

Spectral cues for auditory localization primarily involve the shape and position of the head and outer ears (pinnae), which affect how sound waves are received and processed by the auditory system, helping to determine the location of a sound source.

Question 10

The horizontal axis in auditory localization is called the
A) elevation.
B) depth.
C) azimuth.
D) bradburthy.

Accepted Answer

The term "azimuth" refers to the horizontal angle where a sound source is located. It is the most commonly used term for the horizontal axis in auditory localization.

Question 11

Sound that reaches the ears after bouncing off a wall or a floor is called
A) direct sound.
B) indirect sound.
C) virtual sound.
D) harmonics.

Accepted Answer

Sound that bounces off a surface before reaching the ears is known as indirect sound. It can cause echoes or reverberations and can affect the quality of the original sound. Direct sound is the sound that reaches the ears directly from the source without any reflections or bounces, virtual sound is an illusion of sound created by reflections, and harmonics refer to frequencies that are multiples of the fundamental frequency.

Question 12

Coincidence detectors
A) fire when the ITD equals 0.
B) fire when the ITD is greater than 20.
C) have been found in humans, but not in non-mammals.
D) fire when the ILD is greater than 50.

Accepted Answer

Coincidence detectors in the auditory system fire when the inputs from each ear arrive at the same time, which corresponds to an interaural time difference (ITD) of 0.

Question 13

The precedence effect is
A) the listener perceives the fused sound from two speakers to be originating from the lead speaker.
B) the listener perceives the fused sound from two speakers to be originating from the lag speaker.
C) the listener cannot fuse the sound from two speakers because the lead speaker is too loud.
D) the listener cannot fuse the sound from two speakers because the lag speaker is too loud.

Accepted Answer

The precedence effect, also known as the law of the first wavefront or the Haas effect, refers to the phenomenon where a listener perceives the fused sound from two speakers as originating from the lead speaker, even when there is a slight delay in the sound from the lag speaker. This is because the brain prioritizes the first sound wave to arrive at the listener's ears, and suppresses the delayed sound to create a sense of spatial location and directional hearing. Therefore, choice A is the correct answer.

Question 14

The ___________ is composed of the locations where the ILD and ITD are the same.
A) common region
B) cone of confusion
C) inverse acoustic range
D) Jeffries tube

Accepted Answer

The "cone of confusion" refers to a region of spatial locations where sounds produce the same Interaural Level Difference (ILD) and Interaural Time Difference (ITD), making it difficult to pinpoint the exact location of the sound source.

Question 15

McAlpine's research on gerbils provides evidence for
A) narrowly tuned ITD neurons.
B) broadly tuned ITD neurons.
C) specificity-coding in the auditory cortex.
D) narrowly tuned spectral neurons.

Accepted Answer

McAlpine's research on gerbils suggested that ITD neurons in the auditory cortex are broadly tuned, meaning that they respond to a range of ITDs rather than being narrowly tuned to specific ITD values.

Question 16

Interaural level differences are a cue to auditory localization because the
A) person's head creates an acoustic shadow that prevents high-frequency sounds from reaching the far ear.
B) person's head creates an acoustic shadow that prevents low-frequency sounds from reaching the far ear.
C) medium through which the sound travels can be air, liquid, or solid.
D) acoustic shadow is more likely to occur in an enclosed space than outdoors.

Accepted Answer

The person's head creates an acoustic shadow for high-frequency sounds, making them less likely to reach the ear that is farther from the sound source. This difference in sound level between the two ears helps in localizing the sound source.

Question 17

If there is an interaural time difference, we interpret the sound as coming from
A) directly in front of us.
B) directly behind us.
C) the side.
D) directly above us.

Accepted Answer

An interaural time difference is the difference in time it takes for a sound to reach the two ears. This difference is used to locate the source of the sound in the horizontal plane (left or right). Therefore, we interpret the sound as coming from the side.

Question 18

In the precedence effect, the sound from the far speaker
A) does not contribute to the perception of the sound.
B) only helps sound localization if the time difference is less than 5 milliseconds.
C) only helps sound localization if the time difference is less than 2 milliseconds.
D) contributes to the richness of the sound.

Accepted Answer

The precedence effect involves the brain prioritizing the first sound it hears for localization, but the sound from the far speaker can still contribute to the overall richness and fullness of the sound experience.

Question 19

Garner and Garner showed that smoothing out the nooks of the pinnae
A) results in more accurate localization on all corrdinates.
B) makes it more difficult to locate sounds along the elevation coordinate.
C) results in more accurate localization along the elevation coordinate.
D) does not affect spectral cues for localization.

Accepted Answer

Smoothing out the nooks of the pinnae disrupts the spectral cues that are crucial for accurately locating sounds along the elevation coordinate.

Question 20

Patient J.G. has temporal lobe damage. While this has not affected his ability to locate sounds, he has difficulty recognizing sounds. This case provides evidence for
A) the Jeffress model of auditory localization.
B) what and where pathways in audition.
C) the existence of separate subcortical structures.
D) how and where pathways in audition.

Accepted Answer

Patient J.G.'s difficulty recognizing sounds suggests that the temporal lobe, which processes auditory information and contributes to sound recognition, is damaged. This provides evidence for the "what" pathway in audition, which involves processing and recognition of sound information. The "where" pathway in audition, on the other hand, is involved in sound localization and would be impaired if there were damage to the auditory pathways that determine sound location, which is not the case for Patient J.G. Thus, choice B is the best answer.

Quiz 12: Auditory Localization and Organization

The ____ is important for binaural localization because it is where signals from the left and right ears first meet.

Hofmann et al. had participants wear artificial pinnae for about three weeks. Which of the following was a result of their study?

The cue of interaural level difference is

The ______ is the dominant cue for locating low-frequency sounds along the azimuth.

Interaural time difference detectors

Recanzone (2000) examined localization in A1 and the auditory belt area in monkeys. Results indicated that

Which of the following is NOT a coordinate system for auditory localization?

From the auditory nerve, information is passed through a sequence of subcortical structures. Which of the following reflects the correct sequence?

Spectral cues for auditory localization are provided by

The horizontal axis in auditory localization is called the

Sound that reaches the ears after bouncing off a wall or a floor is called

Coincidence detectors

The precedence effect is

The ___________ is composed of the locations where the ILD and ITD are the same.

McAlpine's research on gerbils provides evidence for

Interaural level differences are a cue to auditory localization because the

If there is an interaural time difference, we interpret the sound as coming from

In the precedence effect, the sound from the far speaker

Garner and Garner showed that smoothing out the nooks of the pinnae

Patient J.G. has temporal lobe damage. While this has not affected his ability to locate sounds, he has difficulty recognizing sounds. This case provides evidence for