Aud Science (5140) Flashcards
power
derivef
mass
basic
time
basic
force
derived
length
basic
pressure
derived
What differentiates a vector quantity from a scalar quantity?
Both have magnitude, and a vector quantity also has [blank]
direction
refers to the amount of change from the equilibrium position
amplitudef
refers to a point within the cycle of simple harmonic motion
phase
the number of full cycles of simple harmonic motion within a period of time
frequency
Regarding sound transmission through air, select all of the statements below that are accurate.
Sound can be described as a disturbance or vibrations of the molecules of an elastic medium.
The air molecules that are in a sound wave’s path move in simple harmonic motion.
Attenuation refers to the reinforcement of air molecules displaced over time.
If you could see a sound wave, you would see changes in air molecule density that emanate from the source and follow a path that is parallel to the floor.
Sound propagation causes regions of relatively high and relatively low pressure that alternate over time.
Sound can be described as a disturbance or vibrations of the molecules of an elastic medium.
The air molecules that are in a sound wave’s path move in simple harmonic motion.
Sound propagation causes regions of relatively high and relatively low pressure that alternate over time.
Combine two tones of the same frequency, that have the same amplitude and starting phase
The resulting tone will have double the amplitude, period stays the same
Combine two tones of the same frequency, that have the same amplitude, and are 180 degrees out of phase
The two tones cancel each other out
Combine two tones of the same frequency, that differ in starting phase by something other than 0 degrees or 180 degrees
The resulting tone will have areas of relatively increased and decreased amplitude throughout the cycle, period stays the same
what is fundamental frequnency (50, 75, 100, 125, 150, 275, 200)
25
Calculate dB IL for a sound intensity of 10-10 watt/m2
Enter the number only.
20
Calculate dB SPL for a sound pressure of 200 micropascals.
Enter the number only
20
Going from 0 dB SPL to 20 dB SPL represents what amount of increase in pressure?
Ten times the pressure (ten-fold increase)
A constant-percentage bandwidth filter is what type of filter?
band pass filter
The attenuation rate or the rejection rate refers to what?
The amount of change in dB per octave
Each point along the basilar membrane has a best or characteristic frequency, where the response is optimal to sounds of a specific frequency.
The response (output) of a healthy basilar membrane at the characteristic frequency to varying levels of sound input is
nonlinear/compressive
With regards to human hearing, the term dynamic range refers to:
The range between the least audible sound and the highest tolerable sound
dynamic range of typical hearing thresholds
100
95
the least amount of amplitude of a stimulus detected
absolute threshold
the least amount of noticeable change along a single dimension
difference threshold
Stimuli are presented in random order, with multiple trials per level.
Method of Constant Stimuli
The patient or study participant has control over the stimulus level.
Method of Adjustment
Threshold is estimated using a series of ascending and descending runs with pre-determined starting levels.
Method of Limits
What makes a psychoacoustic procedure adaptive?
Each successive presentation level is determined based on the patient/subject response
Test assesses the smallest detectable difference between two stimuli that vary in sound pressure.
differential sensitivity
Test assesses the least amount of sound pressure level at which a subject responds 50% of the time.
absolute sensitivity
If we wanted to understand how much to increase a sound level for it to be perceived as double the original sound, what method would we chose?
A direct scaling procedure
convert 60 dB HL to SPL at 2000 Hz using TDH 49/50 headphones.
71
Your patient’s threshold is 25 dB HL. You present a tone at 65 dB HL at the same frequency. At what level in dB SL did you present the tone? Enter the number only.
40
A phon is a measure of
loudness
The reference for a phon is
1000 Hz
Pitch is perceived based on maximum excitation along the basilar membrane.
place model
Bundles of auditory nerve fibers fire at the compression phase of a signal, giving the brain a cue for the period of the signal.
temporal model
Based on spectral representation of the stimulus (information contained in the spectrum).
f
Place Model
Based on the waveform of the stimulus.
temoral model
The duration of a signal can (but may not always) affect which of the following in terms of perception?
bandwidth of the stimulus
perception of tonality
absolute threshold
loudness perception
perception of tonality
absolute threshold
loudness perception
loudness
perceptual
intensity or sound pressure level
physical
frequency
physical
pitch
perceptual
phase
physical
duration
both physical and perceptual
The jnd for frequency (also referred to as dlf) at 1,000 Hz is approximately 5 Hz. The jnd for frequency at 10,000 Hz is approximately 50 Hz. This is an example of
Weber’s law
Frequency selectivity refers to the auditory system’s ability to
detect one sound in the presence of another, different sound
Pitch is perceived based on maximum excitation along the basilar membrane.
place model
Bundles of auditory nerve fibers fire at the compression phase of a signal, giving the brain a cue for the period of the signal.
temporal model
Based on spectral representation of the stimulus (information contained in the spectrum
place model
Based on the waveform of the stimulus.
remporal model
low frequency cue
itd
high frequency cue
ild
arises due to the head shadow effect
ild
sound arrives at each ear at a different point in the cycle (different phase)
itd
transient distortion
spectral splatter
Distortion products are added, which are harmonics of the original signal
Harmonic distortion
Amplitude is reduced at certain frequencies based on the characteristics of the filter
Frequency distortion
What is the “cocktail party effect?
ability to attend to a target in the presence of competing noise
the auditory system takes advantage of the fact that one ear has a more favorable SNR
better ear effect
the auditory system takes advantage of information received from both ears, with different SNRs
binaural squelch
signal threshold is improved when tones to each ear are out of phase
the masking level difference
“copies” of sounds in a reverberant room do not interfere with hearing because of this
echo suppression
guitar string after being plucked
free vibration
tuning fork after being hit with a soft mallet
free vibration
ossicles vibrating because of music
forced vibration
table vibrates when the stem of a vibrating tuning fork is placed on it
forced vibrarion
average dB SPL of a stimulus
RMS amplitude
measure to avoid spectral splatter
5 ms ramped rise time/fall time
input level exceeds maximum output level
harmonic distortion
input level exceeds maximum output level
intermodulation distortion
proportionate change in input and output
linear system
disproportionate change in input and output
nonlinear system
signal and masker are presented to opposite ears; the masker in the opposite ear increases the threshold of the signal
central masking
monaural masking; target signal and masker are presented simultaneously
psychoacoustic masking
the masker is presented either before or after the signal or target
temporal masking
this masking takes place in the cochlea
psychoacoustic masking
this masking takes place in the binaural auditory neural pathway
central masking