Final Exam Flashcards
Outermost portion of the ear
Pinna
How we localize sound at low frequencies
time difference
How we localize sound at high frequencies
level difference between
How we localize sound at mid frequencies
pinna, shape of the outer ear
Model of the ear that accounts for humans being most sensitive to 3500Hz
Open-Closed Tube
The frequency at which we cannot use timing or intensity difference to localize
1000Hz
Main purpose of the middle ear
Impedance matching
Number of bones that make up the middle ear
3
This effect accounts for a doubling of pressure in the middle ear
the lever action of the ossicular chain
This effect accounts for a 20 fold increase of pressure through the middle ear
the surface area of the TM compared to the surface area of the oval window
The smallest bone in the body
Stapes
The membrane through which sound enters the cochlea
Oval window
The membrane separating the scala media from the scala tympani
basilar membrane
These cells amplify auditory signals by 40dB
outer hair cells
This is the name of the fluid in the cochlear duct
endolymph
This is the name of the fluid in the scala tympani and scala vestibuli
perilymph
The theory that accounts for pitch perception
Place theory of hearing/tonotopic organization
The model of the vocal tract which explains its resonances
open closed tube
The approximate length of the vocal tract
0.1725m or 17.25cm
The principle which explains the rapid opening and closing of the vocal folds
Bernoulli’s Principle
The type of waveform generated by the vocal folds
Pulsetrain
The frequencies of formants F1 and F2 for the schwa sound
500 and 1500Hz
A graph showing frequencies along the x-axis and amplitudes along the y-axis
Frequency spectra (Think fourier analysis)
A device containing a volume of air with only a single resonator
Helmholtz resonator
A 3D graph with frequencies along the y-axis and time along the x-axis
Spectrogram (Think schwa)
A random signal weighted toward lower frequencies
Pink noise
A waveform whose fourier spectrum has the same appearance as the time signal
Pulsetrain
This is the most common reference intensity which is also the threshold of hearing.
1x10^-12 w/m^2
If one person speaks at an SIL of 60 dB, then four people speak at this SIL.
66dB
This is how many dBs a sound must increase for it to sound twice as loud.
10dB
This system modifies SILs at various frequencies to account for human sensitivity.
A-Weighting
This is how many dBs a point source SIL is reduced when you double your distance from it.
6dB (10xlog 1/4)
This is the SIL at 1 meter from a point source if its SIL is 30 dB at 16 meters.
10log(1/256) 54dB
This is the frequency shift when both the source and receiver are stationary.
No frequency shift
A frequency shifts higher when a receiver moves this way compared to the source.
Toward the source
This is the effect produced when a source moves toward a receiver at the speed of sound.
Sonic Boom
Frequency is shifted to this when a receiver moves away from a source at the speed of sound.
0
This is what happens to a sound’s wavelength as a source accelerates away from a person.
The length of the wavelength increases because it gets further from the source
This is what happens to sound when a source approaches faster than the speed of sound.
Sonic Boom
A string inverts when it strikes this type of end.
Fixed end
Pressure is at a node at this type of tube end.
Open end
Velocity is at an anti-node at this type of tube end.
Open end
The fundamental wavelength is four times the length of this type of tube.
Open Closed tube
If the third harmonic is 150 Hz, then the second harmonic is this frequency.
100Hz
The fourth harmonic of a 171.5 m long open-open tube has this frequency.
4 Hz
This is the frequency range of human hearing.
20 Hz - 20 kHz (20,000 Hz)
This is why we can’t use loudness changes between the ears to localize low frequencies.
Diffraction
The effect that says that early sounds determine directionality.
Precedence Effect or Haas Effect
This is the law that says that humans are mostly immune from phase differences.
Ohm’s Law of Hearing
This is what happens to the frequency when a string’s tension quadruples.
The strings frequency will double
Sound diffracts down to the ground during this type of temperature gradient.
Sound does not diffract in temp/speed changes. It refracts
A triangle wave needs these harmonics in order to be Fourier synthesized.
Odd Harmonics
This is what happens to formant F1 when you go from a close vowel to an open vowel.
F1 increases
This is the most accurate type of microphone.
Condenser
This is the speed of sound at the ear drum where the temperature is 37oC.
353.2 m/s, s=331+0.6(T in celcius)
