Level up 2
Which do we use primarily for elevation estimation?
monaural cues
The value of the absorption coefficient varies on a scale from ____ to ____ and depends on the frequency of the propagating sound, the thickness and structure of the walls (boundaries), the amount of wall surface, and the type of wall material (i.e., its molecular structure, density, uniformity, and temperature).
0, 1
The reflection coefficient (α) and the absorption coefficient (β), when summed, must equal____
1
The outer ________ (portion) of the ear canal is _________________ while the inner _____________ (portion) is ______________________.
1/3, cartilaginous, 2/3, osseous
If a listener is moving with a velocity of 10 m/s toward a sound source and the sound source is producing a 1000-Hz tone, what is the sound frequency perceived by the listener?
1029.41 Hz
What effect, approximately, do the ear canal and eardrum have, in sound pressure gained, at roughly 3000 Hz, because of their shape and resonance?
11 dB
If a sound pressure is increased 5 fold, in phase, by how many dB will the sound pressure increase? Hopefully the words, in phase, help you realize that the equation you'll be using will be the 20 log one.
14 dB
What is the second resonant frequency of a tube 15.5 cm long that is open at one end and closed at the other?
1645.16 Hz
If two tones of 750 Hz and 748 Hz are played together, how many times per second will what is heard seem to pulse or beat?
2 times per second
The adult external auditory canal is about how long?
2.5 cm
The standard reference for sound pressure level is__
20μ P a
What is the 3rd resonant frequency of a tube 15.5 cm long that is open at one end and closed at the other?
2741.94 Hz
When a sound intensity level doubles, the ratio of the sound is ______, and the resulting sound will _____________ by ________.
2:1, increase, 3 dB
The TM is made up of _____ layers. A person missing part of the fibrous layer might have something that looks like a perforation in their ear although it is not. This is called a ______ segment.
3, monomeric
The lowest or first resonant frequency of the average ear canal is approximately 2833 Hz, because it's effective length is 0.03 m in length. Using the same formula f n = ( 2 n − 1 ) c 4 lwhat would the first resonant frequency of the ear canal be if it's effective length was 0.025 m? Assume c = 340 m/s.
3400 Hz
If two tones of 340 Hz and 346 Hz are played together, what is the basic frequency of the combined tone?
343 Hz
If a sound source is moving with a velocity of 50 m/s toward a listener and the sound source is producing a 3000-Hz tone, what is the sound frequency perceived by the listener?
3517.24 Hz
Two loudspeakers produce a sound intensity level of 40 dB IL. If they are played together, what is the overall sound intensity level? Note: When entering your answer, just put in the number. If you try to label it with dB or something like that, Canvas will probably mark it wrong. Just enter the number.
43
If a sound source is moving with a velocity of 43 m/s away from a listener and the sound source is producing a 500-Hz tone, what is the sound frequency perceived by the listener?
443.86 Hz
At which angle are we most sensitive to 3000 Hz? I'm asking about where we get the most gain for this frequency.
45 degrees
What is the sound pressure level of a 5000 μPa sound?
48 dB SPL
If a 45 dB SPL sound is doubled, in phase, what would the resulting sound level be?
51 dB SPL
What is the lowest resonant frequency of a tube 15.5 cm long that is open at one end and closed at the other?
548.39 Hz
If two tones of 340 Hz and 346 Hz are played together, what is the beat frequency of the combined tone?
6 Hz
If the sound pressure produced by one loudspeaker is measured at 60 dB SPL and we add a second loudspeaker also producing 60 dB SPL, what is the total sound pressure level?
63 dB SPL
If a swarm or hive of 200 bees produces a sound of 75 dB, what do you estimate the level to be if an additional 50 bees are added?
75.97 dB
Without using a calculator, estimate the intensity level when the following sources are combined: 78 dB IL, 23 dB IL, 80 dB IL, 45 dB IL.
82 dB IL
Antitragus
A small projection obliquely opposite the Tragus on the superior border of the lobe of the ear.
Tragus
Cartilaginous projection anterior to the external opening of the ear
triangular fossa
Depression between the crura. The second deepest depression of the ear.
0 dB SPL means the absence of sound.
False
You should use cotton swabs (q-tips) to clean cerumen from your ear canals because cerumen is a waste product.
False
As we've learned from previous modules, high frequency sounds, or those with a short wavelength, don't diffract and bend around obstacles larger than the wavelength, causing an acoustic shadow. With that in mind, which of the following is more likely to contribute to our ability to localize higher frequency sounds.
ILDs (Interaural level differences)
The B in the abbreviation dB is capitalized because...
It was named after Alexander Graham Bell
What are you looking at if an examination of the tympanic membrane with an otoscope shows the cone of light at about 7:00 o'clock and the manubrium of the malleus appears at about 11:00 o'clock?
Left TM
Identify landmark "A."
Manubrium of the Malleus
Module 7 Chapter 8 Terms
Pick this answer
Which side of the ear are we looking at.
Right
SNR stands for
Signal to noise ratio
Antihelix
The inner rim of the ear. It starts at the superior border of the lobe and continues upward until it ends by becoming the crura. It forms the superior and posterior walls of the concha.
Lobule (ear lob)
The lowest part of the Pinna, composed of skin and fat, no cartilage
Helix
The out fold of the pinna that curves around the outside edge and ends at the crus of the helix
The ear structure consists of three major parts:
The outer, middle, and inner ear
The Out Ear consists if
The pinna (auricle), external auditory canal (ear canal), and the tympanic membrane (eardrum) where the EAC terminates.
Pinna
The structure if the outer ear that extends out from the side of the head at about a 30o angle around the external auditory meatus (opening)
If separate sound sources are being combined, you should always use the formula for combining sound levels produced by equal intensity sound sources, which is based on the intensity rules for changes in level.
True
In the case of dB IL and dB SPL, the unit is the same (dB) but the reference points are different.
True
Logarithmic units allow for the numerical representation of physical magnitudes in a manner that correlates to human perception and allow for the compression of a large range of physical values into a much smaller and more manageable range.
True
The standard reference for sound intensity level is 10-12 w/m2. So a sound of 20μPa is the same as that produced from an intensity level of 10-12 w/m2.
True
The tympanic membrane is cone shape and at the center of the TM, where the TM makes contact with the Malleus is called the_________
Umbo
scaphoid fossa
a groove located immediately anterior to the helix, which runs down the posterior portion of the pinna
The ability of the medium and its boundaries to absorb the energy of sound waves is characterized by a quantity called the
absorption coefficient
Identify landmark 'f.'
antihelix
The process of determining the direction on the horizontal plane at which a sound is arriving at the listener is called_____.
azimuth estimation
Because sounds travel faster through the denser air, sound waves tend to refract or bend toward____________
cold air
If two overlapping waves of the same wavelength are in- phase (i.e., their compressions and rarefactions coincide), their interference is called_____.
constructive interference
Classrooms with a ____________ have reflected speech sounds that overlap and mask (cover) the teacher's speech. This ___________ the ability of all children (and especially children with hearing loss) to hear a clear signal.
high RT, decreases
Which part of the pinna does not have underlying cartilage?
lobule
Doubling the sound pressure level (SPL) can result in an increase of 6 dB. However, this requires that, if you are adding a second source signal, the two need to be correlated in___________. Since that correlation doesn't occur much naturally, we should use the formula for combining sound sources, which is based on the ________ rules for changes in level.
phase, intensity
You might consider a room that is considered "dead" to have reverberation times that are__________.
short
A sound wave can bend or change direction when it encounters a medium with a different density and stiffness. This is called_____.
sound refraction
Auricular Tubercle
superior-posterior bulge on the helix
Identify landmark 'm.'
triangular fossa
The log, with base 10, of 1000 is____
3
Reverberation time (RT) is calculated as the amount of time it takes for a sound to decrease in intensity by___
60 dB
Convert 10-6w/m2 to sound intensity level.
60 dB IL
Identify the landmark 'j.'
Concha cavum
Identify "A."
Outer ear
Module 7 Quiz
Pick this answer
Which of the following is part of the pinna?
Scaphoid fossa
For cases where the dimensions of the obstacle are much larger than the wavelength, that is d >>λ, the wave will be reflected from the obstacle, creating an acoustic shadow, which is an area behind an obstacle that the direct sound wave does not enter. One's head might be considered an obstacle causing an acoustic shadow if sound reaches one ear first and the frequency is relatively_____. If the average distance between the ears is roughly 21 cm, which frequency would most likely cause an acoustic shadow at the ear opposite to the one at which sound arrived first?
high, >1600 Hz
Blowing air over a soda bottle to make a "hooting" noise is an example of a Helmholtz resonator. Looking at the equation f = c 2 π A h V Blowing over a soda bottle (using it like a flute) almost full of soda will mean the volume of the resonator is small. If the bottle is almost empty, the volume of air would be large. The frequencies of these respective scenarios would be_____
high, low
