Sound, the Ear and Auditory Perception Flashcards
What are the 3 characteristics of sound waves?
1) Frequency (Hertz)
2) Amplitude (or intensity)
3) Complexity
What are the 3 perceptual phenomena of sound waves?
1) Pitch
2) Loudness (decibels)
3) Timbre (quality of the sound)
Match the characteristic of sound waves with the perceptual phenomenon
Frequency
a. Pitch
b. Loudness (decibels)
c. Timbre (quality of the sound)
a. Pitch
Match the characteristic of sound waves with the perceptual phenomenon
Amplitude (or intensity)
a. Pitch
b. Loudness (decibels)
c. Timbre (quality of the sound)
b. Loudness (decibels)
Match the characteristic of sound waves with the perceptual phenomenon
Complexity
a. Pitch
b. Loudness (decibels)
c. Timbre (quality of the sound)
c. Timbre (quality of the sound)
Match the perceptual phenomenon of sound waves with the characteristic of the sound wave
Pitch
a. Frequency (Hertz)
b. Amplitude (or intensity)
c. Complexity
a. Frequency (Hertz)
Match the perceptual phenomenon of sound waves with the characteristic of the sound wave
Loudness (decibels)
a. Frequency (Hertz)
b. Amplitude (or intensity)
c. Complexity
b. Amplitude (or intensity)
Match the perceptual phenomenon of sound waves with the characteristic of the sound wave
Timbre (quality of the sound)
a. Frequency (Hertz)
b. Amplitude (or intensity)
c. Complexity
c. Complexity
What is frequency measured in?
Hertz (number of waves per second)
What is hertz?
Number of waves per second
The higher the frequency, the…?
a. Shorter the wavelength
b. Longer the wavelength
a. Shorter the wavelength
What is the typical human hearing range?
20 – 20,000 Hz
What is the frequency of the middle C on a piano?
261.63 Hz
The longer the wavelength, the…?
a. Higher the frequency
b. Lower the frequency
b. Lower the frequency
The shorter the wavelength, the…?
a. Higher the frequency
b. Lower the frequency
a. Higher the frequency
The higher the frequency, the…?
a. Longer the wavelength
b. Shorter the wavelength
b. Shorter the wavelength
The lower the frequency, the…?
a. Longer the wavelength
b. Shorter the wavelength
a. Longer the wavelength
Which sound has the higher frequency?
a. Infrasound
b. Ultrasound
b. Ultrasound
Which sound has the lower frequency?
a. Infrasound
b. Ultrasound
a. Infrasound
What value is considered the lowest frequency on the piano?
30 Hz
What value is considered the highest frequency on the piano?
4000 Hz
What value can ultrasound go up to?
10,000Hz
What does amplitude measure?
Loudness
What is loudness measured by?
Amplitude
The higher the amplitude, the…?
a. Louder the sound
b. Quieter the sound
a. Louder the sound
The smaller the amplitude, the…?
a. Louder the sound
b. Quieter the sound
b. Quieter the sound
True or False?
As you age, you can no longer hear higher frequencies
True
What are the average decibel level and pressure levels of rock bands?
160dB and 20,000
What are the average decibel level and pressure levels of spacecraft launch?
180dB and 200,000
What are the average decibel level and pressure levels of the threshold of pain?
140dB and 2000
What are the average decibel level and pressure levels of the threshold of hearing?
0dB and 0.0002
What are the average decibel level and pressure levels of shouting?
80dB and 2
What are the average decibel level and pressure levels of conversation?
60dB and 0.2
What are the average decibel level and pressure levels of a whisper?
40dB and 0.02
True or False?
A complex wave is when 2 sounds have different frequencies but the shape of the wave (pitch) is the same
False
A complex wave is when 2 sounds have the same frequency but the shape of the wave (pitch) is different
What is a complex wave?
A complex wave is when 2 sounds have the same frequency but the shape of the wave (pitch) is different
When 2 sounds have the same frequency but the shape of the wave (pitch) is different
This is known as…?
Complex waves
The wavelength of the longest component. This determines the pitch of the sound
This is known as…?
Fundamental frequency
What is fundamental frequency?
The wavelength of the longest component
This determines the pitch of the sound
The lowest frequency produced by any particular instrument
What determines the pitch of the sound?
Fundamental frequency
What determined the sound quality?
Harmonics
Sound quality is also known as…?
Timbre
What is a Fourier analysis?
Taking apart complex waves and looking at the harmonics that overlay the frequencies
Taking apart complex waves and looking at the harmonics that overlay the frequencies
This is known as…?
Fourier Analysis
Name the 6 parts of the ear that are involved with the hearing of sound
- Outer ear
- Middle ear
- Inner ear
- Auditory nerve
- Cochlea
- Semicircular canals
What is the function of the vestibular system?
To detect the position and movement of our head in space
To detect the position and movement of our head in space
What is responsible for this?
Vestibular System
What is the vestibular-ocular reflex?
A reflex that helps stabilize the visual field during head movements
It occurs in response to head movement and leads to the eyes moving in the opposite direction to maintain a steady gaze.
A reflex that helps stabilize the visual field during head movements
It occurs in response to head movement and leads to the eyes moving in the opposite direction to maintain a steady gaze.
This is known as…?
The vestibular-ocular reflex
What 4 parts are involved in the vestibular-ocular reflex?
- Semicircular canal
- Endolymph
- Nerves
- Cupula
What happens in the cross-section of the cochlear?
Hair cells in the organ of Corti detect vibrations in the Basilar membrane
Hair cells in the organ of Corti detect vibrations in the Basilar membrane
Where does this take place?
Cross-Section of the Cochlear
In the cross-section of the cochlear, what are the roles of hair cells in the organ of Corti?
They detect vibrations in the Basilar membrane
What detect vibrations in the Basilar membrane?
Hair cells in the organ of Corti
How do hair cells change their firing rate?
By being bent
True or False?
Hair cells change their firing rate when they are bent
True
How sensitive are hair cells in the cochlear?
Hair cells are sensitive to movement of 10 picometres
What does tonotopic mean?
When cells respond preferentially to a particular frequency
When cells respond preferentially to a particular frequency
This is known as…?
Tonotopic
True or False?
Hair cells respond preferentially to a particular frequency
True
True or False?
Hair cells are not tonotopic
False. Hair cells are tonotopic
True or False?
The visual system is tonotopic
False. The visual system is retinotopic
The tonotopic organisation is maintained as far as ……. in the ………
a. Primary auditory cortex
b. Temporal lobe
Neurones next to one another respond to …?
Neighbouring frequencies
What are the 5 types of auditory transduction?
1) Air pressure changes (kinetic)
2) Vibration of eardrum -> middle ear -> oval window (mechanical)
3) Cochlear fluid flows (kinetic)
4) Hair cells bend (mechanical)
5) Auditory nerve fires (neural)
What kind of energy is induced by air pressure changes?
Kinetic
What kind of energy is induced due to the vibration of eardrum -> middle ear -> oval window?
Mechanical
What kind of energy is induced due to cochlear fluid flows?
Kinetic
What kind of energy is induced due to hair cell bend?
Mechanical
What kind of energy is induced due to auditory nerve fires?
Neural
What are the 3 types of auditory perception?
- Pitch and loudness
- Location in space
- Grouping
What does pitch depend on?
Frequency
What does loudness depend on?
Amplitude
Are pitch and loudness independent of each other?
No
More intense low-frequency sounds are perceived as ….. pitch
a. Higher pitch
b. Lower pitch
b. Lower pitch
More intense high-frequency sounds are perceived as ….. pitch
a. Higher pitch
b. Lower pitch
a. Higher pitch
Perception of loudness affected by…?
Frequency
Low-frequency sounds need to be …… to be perceived as equally loud
a. More intense
b. Less intense
a. More intense
True or False?
Low-frequency sounds need to be less intense to be perceived as equally loud
False
Low-frequency sounds need to be more intense to be perceived as equally loud
True or False?
Sounds with higher frequencies are often perceived as louder than sounds with lower frequencies, even if they are played at the same intensity
True
What is auditory space perception?
Identifying the direction from which a sound is coming and estimating the distance to the sound source
Identifying the direction from which a sound is coming and estimating the distance to the sound source
This is known as…?
Auditory space perception
Clues that allow us to recognise where and how far away a sound is coming from using only one ear
This is known as…?
Monoaural space perception
What is monoaural space perception?
Clues that allows us to recognise where and how far away a sound is coming from using only one ear
What are the 2 clues related to monoaural space perception?
1) Loudness
2) Doppler effect
We need binaural space perception to perceive where a sound is coming from
True or False?
True
Why do we hear interaural intensity differences?
Because our ears are located on the opposite sides of our heads and due to the attenuation of the sound wave as it passes through our head
The loss of hearing on one side of the ear that is a result of the head being between a sound source and the inner ear. When one ear has a hearing loss, then it’s up to the other ear to process the sound information from both sides of the head
This is known as…?
The “head shadow” effect
What is the “head shadow” effect?
The loss of hearing on one side of the ear that is a result of the head being between a sound source and the inner ear. When one ear has a hearing loss, then it’s up to the other ear to process the sound information from both sides of the head
What are interaural intensity differences?
A sound coming from the right side of your body is more intense in your right ear than in your left ear, and vice versa for sounds from the left
Due to the shadowing of the sound wave by the head (head shadow), a sound coming from a source located to one side of the head will have a higher intensity, or be louder, at the ear nearest the sound source.
A sound coming from the right side of your body is more intense in your right ear than in your left ear, and vice versa for sounds from the left
due to the shadowing of the sound wave by the head (head shadow), a sound coming from a source located to one side of the head will have a higher intensity, or be louder, at the ear nearest the sound source.
This is known as…?
Interaural intensity differences
What role does the outer ear have?
Channel sound waves into the auditory canal and protects the auditory canal
What happens in the auditory canal?
Sound waves reach the ear drum, which will vibrate (like a drum)
Change air pressure into mechanical motion of the eardrum moving
What part of the ear makes up the vestibular system?
Semicircular canals
True or False?
Semicircular canals are fluid-filled structures
True
What fluids are inside the 3 semicircular canals?
Endolymph
Where can we find Endolymph?
In the 3 semicircular canals
What happens to Endolymph when you move your head?
Endolymph in the semicircular canals move and tells the nervous system that your head has turned and moved
What does the cupula do?
Endolymph in the semicircular canals moves the cupula (kind of like a door hinge) and the movement is detected and sent to the nervous system
How come you feel like you’re still turning after spinning round and round?
The Endolymph fluids in your inner ear (semicircular canals) are still moving and fooling your brain into thinking that you’re still turning
What problems might people with vestibular system damage?
They can have a lot of vertigo, dizziness and difficulty with coordination
What happens in the vestibular-ocular reflex?
Your brain detects that you’ve turned your head. You are able to move your eyes rapidly to compensate for the movement of your head (reflex)
What reflex helps us keep things in focus as we walk around?
Vestibular-ocular reflex
What bones are the ear drums attached to?
Ossicles
What happens to the ossicles when the eardrum vibrates?
Ossicles move, which also induces movement in the oval window
Apart from the eardrum, what else are ossicles attached to in the middle ear?
Oval window
When you listen to your own voice, it sounds different to the voice that you hear of yourself in a recording
Why does this happen?
Because when you hear your own voice whilst talking, you hear your voice as sound waves being transmitted through the air as well as the vibration of your skull and jaw (simply = voice that is conducted through the bones of your skull)
What happens after the sound has reached the oval window?
Movement is carried through the cochlear
What happens within the cochlear?
The oval window vibrates and produces a wave in the Basilar membrane
As the basilar membrane vibrates, what part of the cochlear becomes deflected?
Hair cells
How come hair cells change their firing rate when bent?
The basilar membrane deflects/bends the hair cells and potassium ions go in
This produces transmitter release and action potential firing
What is the Doppler effect? Give an example as well
Higher frequency of sounds tend to be lost over longer distances
e.g. Hearing a very fast car passing and it makes a eeeeerrr sound (gives clues of how far away the sound is coming from)
e.g. You hear the high pitch of the siren of the approaching ambulance, and notice that its pitch drops suddenly as the ambulance passes you.
What is the interaural time difference that we can detect?
Simply = We can detect time differences of sounds at around…? How many seconds?
0.07 seconds
True or False?
We are good at detecting where sound is coming from in the vertical domain
False. We are poor at detecting where sound is coming from in the vertical domain. We have to actually move our heads to detect the direction of the sound to perceive vertical location of sound source
Auditory grouping or streaming is similar to …… in vision
Figure-ground separation
How can we group audio/sounds? List 3 ways
Grouped into streams by proximity/closeness in:
1) Space
2) Time
3) Frequency
The appearance of an auditory ascending scale is known as…?
Simply = A sound that appears as if it’s going up forever
Shepard Tones
What are Shepard tones?
The appearance of an auditory ascending scale
Simply = A sound that appears as if it’s going up forever
How can we hear Shepard tones? How does this illusion work?
This works because there is a mixture of tones, which induces an ambiguous fundamental pitch/frequency
You always feel like the next note is higher but it actually cycles through the same notes over and over again
Speech without acoustic/speech cues is known as..?
Sine-wave speech
What is sine-wave speech?
Speech without acoustic/speech cues
What can help us recognise a speech without acoustic/speech cues?
Having knowledge of what the sentence/speech sounds like helps us recognise the sine-wave speech
