Final Exam

Question 1

Outermost portion of the ear

Answer 1

Pinna

Question 2

How we localize sound at low frequencies

Answer 2

time difference

Question 3

How we localize sound at high frequencies

Answer 3

level difference between

Question 4

How we localize sound at mid frequencies

Answer 4

pinna, shape of the outer ear

Question 5

Model of the ear that accounts for humans being most sensitive to 3500Hz

Answer 5

Open-Closed Tube

Question 6

The frequency at which we cannot use timing or intensity difference to localize

Answer 6

1000Hz

Question 7

Main purpose of the middle ear

Answer 7

Impedance matching

Question 8

Number of bones that make up the middle ear

Answer 8

3

Question 9

This effect accounts for a doubling of pressure in the middle ear

Answer 9

the lever action of the ossicular chain

Question 10

This effect accounts for a 20 fold increase of pressure through the middle ear

Answer 10

the surface area of the TM compared to the surface area of the oval window

Question 11

The smallest bone in the body

Answer 11

Stapes

Question 12

The membrane through which sound enters the cochlea

Answer 12

Oval window

Question 13

The membrane separating the scala media from the scala tympani

Answer 13

basilar membrane

Question 14

These cells amplify auditory signals by 40dB

Answer 14

outer hair cells

Question 15

This is the name of the fluid in the cochlear duct

Answer 15

endolymph

Question 16

This is the name of the fluid in the scala tympani and scala vestibuli

Answer 16

perilymph

Question 17

The theory that accounts for pitch perception

Answer 17

Place theory of hearing/tonotopic organization

Question 18

The model of the vocal tract which explains its resonances

Answer 18

open closed tube

Question 19

The approximate length of the vocal tract

Answer 19

0.1725m or 17.25cm

Question 20

The principle which explains the rapid opening and closing of the vocal folds

Answer 20

Bernoulli’s Principle

Question 21

The type of waveform generated by the vocal folds

Answer 21

Pulsetrain

Question 22

The frequencies of formants F1 and F2 for the schwa sound

Answer 22

500 and 1500Hz

Question 23

A graph showing frequencies along the x-axis and amplitudes along the y-axis

Answer 23

Frequency spectra (Think fourier analysis)

Question 24

A device containing a volume of air with only a single resonator

Answer 24

Helmholtz resonator

Question 25

A 3D graph with frequencies along the y-axis and time along the x-axis

Answer 25

Spectrogram (Think schwa)

Question 26

A random signal weighted toward lower frequencies

Answer 26

Pink noise

Question 27

A waveform whose fourier spectrum has the same appearance as the time signal

Answer 27

Pulsetrain

Question 28

This is the most common reference intensity which is also the threshold of hearing.

Answer 28

1x10^-12 w/m^2

Question 29

If one person speaks at an SIL of 60 dB, then four people speak at this SIL.

Answer 29

66dB

Question 30

This is how many dBs a sound must increase for it to sound twice as loud.

Answer 30

10dB

Question 31

This system modifies SILs at various frequencies to account for human sensitivity.

Answer 31

A-Weighting

Question 32

This is how many dBs a point source SIL is reduced when you double your distance from it.

Answer 32

6dB (10xlog 1/4)

Question 33

This is the SIL at 1 meter from a point source if its SIL is 30 dB at 16 meters.

Answer 33

10log(1/256) 54dB

Question 34

This is the frequency shift when both the source and receiver are stationary.

Answer 34

No frequency shift

Question 35

A frequency shifts higher when a receiver moves this way compared to the source.

Answer 35

Toward the source

Question 36

This is the effect produced when a source moves toward a receiver at the speed of sound.

Answer 36

Sonic Boom

Question 37

Frequency is shifted to this when a receiver moves away from a source at the speed of sound.

Answer 37

0

Question 38

This is what happens to a sound's wavelength as a source accelerates away from a person.

Answer 38

The length of the wavelength increases because it gets further from the source

Question 39

This is what happens to sound when a source approaches faster than the speed of sound.

Answer 39

Sonic Boom

Question 40

A string inverts when it strikes this type of end.

Answer 40

Fixed end

Question 41

Pressure is at a node at this type of tube end.

Answer 41

Open end

Question 42

Velocity is at an anti-node at this type of tube end.

Answer 42

Open end

Question 43

The fundamental wavelength is four times the length of this type of tube.

Answer 43

Open Closed tube

Question 44

If the third harmonic is 150 Hz, then the second harmonic is this frequency.

Answer 44

100Hz

Question 45

The fourth harmonic of a 171.5 m long open-open tube has this frequency.

Answer 45

4 Hz

Question 46

This is the frequency range of human hearing.

Answer 46

20 Hz - 20 kHz (20,000 Hz)

Question 47

This is why we can't use loudness changes between the ears to localize low frequencies.

Answer 47

Diffraction

Question 48

The effect that says that early sounds determine directionality.

Answer 48

Precedence Effect or Haas Effect

Question 49

This is the law that says that humans are mostly immune from phase differences.

Answer 49

Ohm's Law of Hearing

Question 50

This is what happens to the frequency when a string's tension quadruples.

Answer 50

The strings frequency will double

Question 51

Sound diffracts down to the ground during this type of temperature gradient.

Answer 51

Sound does not diffract in temp/speed changes. It refracts

Question 52

A triangle wave needs these harmonics in order to be Fourier synthesized.

Answer 52

Odd Harmonics

Question 53

This is what happens to formant F1 when you go from a close vowel to an open vowel.

Answer 53

F1 increases

Question 54

This is the most accurate type of microphone.

Answer 54

Condenser

Question 55

This is the speed of sound at the ear drum where the temperature is 37oC.

Answer 55

353.2 m/s, s=331+0.6(T in celcius)