Aud Sci Flashcards
What will increasing stiffness result in?
Increased rate of vibration
What will increased mass result in?
Decreased rate of vibration
What happens when there are two sound waves and they have these properties:
both sound waves have the same amplitude
both sound waves have the same frequency
the two sound waves are 180o out of phase
Since they are exactly 180 degrees out of phase, they would cancel each other out
What is on the x-axis of a sine wave?
Time
What is a basic quantity?
The simplest quantities and they consist of time, mass, and length
What are derived quantities?
Any combination of basic quantities
What is a scalar?
Magnitude
What is a vector?
Magnitude and direction
What is simple harmonic motion?
Force is applied to the object
The object is displaced from equlibrium (inertial force)
The object reaches it’s maximum displacement
The elastic restoring force tries to bring it back to equilibrium
The object overshoots equilibrium and moves in the opposite direction (inertial force)
The object reaches its maximum displacement on the other side
The elastic restoring force tries to bring it back to equilibrium again
The object overshoots equilibrium and moves in the opposite direction again (inertial force)
This continues until friction eventually slows the object down and it returns to equilibrium again
How does sound energy travel from the source through air?
A force is applies to the tuning fork which causes it to vibrate in simple harmonic motion
The movement of the tuning fork displaces the air molecules around the fork
These air molecules begin with simple harmonic motion as well
These air molecules will come in contact with other air molecules as they reach their maximum displacement in the cycle of simple harmonic motion
These air molecules will also begin moving with simple harmonic motion
Since all of the air molecules are vibrating with simple harmonic motion, there are areas of rarefaction (low concentration) and areas of compression (high concentration)
This sequence of simple harmonic motion and stimulating surrounding air molecules continues until the sound from the sound source stops or until the distance from the sound source becomes too great and friction attenuates the movement of the air molecules
What is rarefaction?
Low concentration
What is compression?
High concentration
How is period calculated?
T=1/f
Does periodic sound have a tonal quality?
Yes
Is an aperiodic sound comprised of frequencies that have no particular mathematical relationship to each other?
Yes
Does a periodic sound have compressed harmonics?
Yes
Is a single pure tone periodic?
Yes
If a sound has a sound pressure level of 0 dB SPL, what is the pressure of that sound in micropascals?
20
What is pressure?
Force per unit area
Measured at a particular location away from the sound source
What is power?
Work per unit time
Property of the sound source
What is intensity?
Power per unit area
Describes the flow of sound
What is rms amplitude?
Average amplitude
What are harmonics?
Harmonics are multiples of the fundamental frequency, and individual components of a harmonic complex
What does it mean to say that sounds within a harmonic complex are harmonically related?
It means that sounds within a harmonic complex are multiples of the same largest common denominator (the fundamental frequency)
Which type of dB is greater, dB IL or dB SPL?
They are equal to each other
What is the log of 100?
2
What makes a psychoacoustic procedure adaptive?
It is dependent on the patient’s response to the previous stimulus
T/F: According to our current understanding of measuring perceptual sensitivity, a subject or patient would never respond to a stimulus presented below their measured threshold of sensitivity for that sound
False
Will someone with a liberal criterion present with thresholds that are relatively better or poorer?
Relatively better
Are shorter sounds ok for valid testing?
No, they are perceived more like a click
Need to be at least 200 to 300 ms
For normal hearing listeners, a doubling of loudness is approximately equivalent to an increase of how many dB?
10
What is the jnd for intensity?
1 dB or better, depending on the presentation level
What is the jnd for frequency?
Approximately 0.5% of the frequency
What is the jnd for duration?
As short as 2-3 ms
Why would the jnd be different at 2000 Hz than at 1000 Hz?
It is based on a percentage of the original frequency
What are 4 factors that affect threshold estimation?
Internal noise, attention, understanding of test, variable magnitude of stimulus
What are the 5 parameters for measuring thresholds behaviorally?
- Starting level
- Stopping rule
- Step size
- What is determining threshold
- How is the sound presented (medium)
True or false: loudness perception is dependent upon the frequency of the stimulus
True
Review loudness growth curves
What is the phon scale?
There is no particular relationship implied with 10 of this unit and 5 of this unit
What is the sone scale?
10 of this unit would be double the loudness of 5 of this unit
Is SPL pretty much always more than HL?
Yes
Review question 18 on exam 2
What is differential sensitivity?
Test that assess the smallest detectable difference between two stimuli that vary in sound pressure
What is absolute sensitivity?
Test that assesses the least amount of sound pressure level at which a subject responds 50% of the time
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
The cochlea is nonlinear, meaning that the amount of gain differs based on input level. Is more gain applied at low-level inputs, mid-level inputs, or high-level inputs?
Low level inputs