Quiz 3

Question 1

Frequency Selectivity is the ability of the ________ system to separate out the individual components from a _______ sound

Answer 1

Auditory

Complex

Question 2

Frequency Selectivity accounts for many ________ phenomena and is often measured using a _______ ________

Answer 2

auditory
masking paradigm

Question 3

Masking is the amount by which the ______ for one sound is ______ by the presence of another sound

Answer 3

threshold
raised

Question 4

Noise Power Density is ______ per unit time in a _ Hz wide band a noise; when expressed with reference to dB IL, is also called the _________ _________n(level per cycle)

Answer 4

Energy
Spectrum level

Question 5

Tone-on-tone (or NBN) masking studies reveal masking patterns with _______ ______ on the low-frequency side and ______ ______ slopes on the high frequency side

Answer 5

Steep slopes
Less steep

Question 6

Masking grows in a _____-______ fashion on the _____-frequency side

Answer 6

non-linear
high

Question 7

Fletchers hypothesis is when masking a tone by a ______ band noise and only a _______ band of that noise contributes to the ________

Answer 7

narrow
broad
masking

Question 8

Fletcher’s experiments estimated the ______ of the critical bands, which today are known as the _______ _______

Answer 8

widths
critical ratios

Question 9

Fletcher assumed, for simplicity, that the CB (auditory filter) was _______

Answer 9

Rectangular

Question 10

More direct methods have determined the critical bands to be . time the critical ratio (or CR is . time the CB)

Answer 10

2.5
0.4

Question 11

Listener responses ______ when stimuli have bandwidths _____ or _____ than the CB

Answer 11

Vary
Narrower
Wider

Question 12

The auditory filter is not _________, but rather is a filter with a ________ top and _______ edges

Answer 12

rectangular
rounded
sloping

Question 13

The critical band is a measure of the “_______” _________ of the filter

Answer 13

effective bandwidth

Question 14

The equivalent rectangular bandwidth of a filter equals the BW of a perfect _________ filter with a pass band equal to a specified filter and transmitting the same power of white noise as the specified filter

Answer 14

rectangular

Question 15

Noise power is divided by the _________ level, and the ________ is the bandwidth of a rectangle with the total power of the noise and the spectrum level of the noise

Answer 15

Spectrum
ERB

Question 16

Noise is a sound with _________ amplitudes that vary over time

Answer 16

Instantaneous

Question 17

“_____ noise” is the term used for a noise with ____ frequencies between certain frequency limits (noise bandwidth)

Answer 17

white
all

Question 18

White noise intensity is measured in
(1):
(2):

Answer 18

(1) Total power
(2) Spectrum level (average power in a 1 Hz wide noise band)

Question 19

When spectrum level of a white noise is known, overall ______ can be derived using the formula: ___ = ___ + 10 log BW

Answer 19

Intensity
OAL = LPC + 10 log BW

Question 20

When Overall power of a white noise is known, the ______ level can be derived using the formula: ___ = ___ - 10 log BW

Answer 20

Spectrum
LPC = OAL - 10 log BW

Question 21

Ex.

If a noise contains frequencies between 1 and 10,000 Hz and the overall level is 100 dB SPL, then the spectrum level is?

Answer 21

LPC = 100 - 10 log 10^4 = 60 dB SPL

Question 22

Ex.

If a noise has a spectrum level of 40 dB and the BW is again 10,000 Hz, then the overall level is?

Answer 22

OAL = 40 +10 log 10^4 = 80 dB SPL

Question 23

The cochlea functions as a series of __________ filters with bandwidths equal to the critical bandwidth

Answer 23

overlapping

Question 24

Critical band varies from less than ___ Hz at low frequencies to about / octave at high frequencies

Answer 24

100 Hz
1/3 octave

Question 25

Audible range has __ critical bands; these are _________ so that any frequency has a CB centered on it

Answer 25

24 Continuous

Question 26

Several methods are avalible to define the ________ of the BM (and its frequency resolving power)

Answer 26

sharpness

Question 27

Each point on basilar membrane is a __________ filter with a particular CF, BW and roll-offs. A _ dB bandwidth can be used, but measurement is often difficult, therefore, the __ dB down point is often used

Answer 27

bandpass 3 dB 10 dB

Question 28

Because many filters (including the BM) the bandwidth is not _______, a relative measure - BW/CF - is used. The reciprocal - CF/BW - is a measure of _______, which is known as the _ (for quality) factor, when the 10 dB point is used, this is called __

Answer 28

Constant tuning Q Q sub 10

Question 29

Q Ex. For a BW of 100 Hz and a CF of 1000 Hz, relative bandwidth (BW/CF) is? For a BW of 50 Hz and a CF of 1000 Hz, relative BW is? For a BW of 10 Hz and a CF of 1000 Hz, relative BW is? A Q factor of 4.35 equals a _/_ octave BW

Answer 29

.1 and the Q factor (CF/BW) is 10 .05 and the Q factor is 20 .01 and the Q factor is 100 1/3

Question 30

What are the two methods to determine auditory filter shape, including:

Answer 30

1. Psychophysical tuning functions 2. Notched noise methods

Question 31

Psychophysical tuning curves you present a _____ intensity, low-level tone and mask it with a variable intensity tone or NBN. The level of the masker needed just to mask the signal is determined. Graph of results is the ______, which, when inverted, is the ________ filter

Answer 31

variable PTC auditory filter

Question 32

Psychophysical tuning curves are similar to _________ tuning functions; however, they are NOT the same

Answer 32

Neural

Question 33

Neural curves are ___________, obtained from single neurons. The PTC is __________, obtained behaviorally from a group of neurons

Answer 33

physiological psychophysical

Question 34

Listeners can and do use "_____ ______" listening to improve performance in noise

Answer 34

off frequency

Question 35

Some listeners with high frequency hearing loss are not able to use _____ frequency energy effectively (based on the AI); that is, their speech recognition performance is ______ with increasing high frequency energy

Answer 35

high poorer

Question 36

Cochlear "dead regions" are areas of the cochlea in which _____ ( or nerve fibers) are not functioning

Answer 36

IHCs

Question 37

_______ has developed a protocol for measuring dead regions: 1. Thresholds are measured and plotted in dB SPL 2. Threshold in re- measured in shaped, ipsilateral, broad-band noise - threshold equalizing noise (TEN), which is calibrated in dB/ERB 3. Normal ears and OHC-damaged ears show equal thresholds in dB SPL, with masked threshold in dB SPL equal to masker level in dB/ERB. Ears with dead regions show masked thresholds exceeding the unmasked theta and the expected masked threshold by > 10 dB

Answer 37

Moore

Question 38

To reduce off-frequency listening, a ________ with a notch (varying in width) at the signal frequency is used, and the threshold of the signal is determined as a function of notch width

Answer 38

masking

Question 39

With level effects the auditory filter _________ with increasing level, particularly on the ____-frequency side ("passive" vs. "active" cochlear processes)

Answer 39

broadens low

Question 40

The auditory filters account for many auditory phenomena, such as complex sound _____, frequency ______, _____, and loudness _______

Answer 40

detection selectivity Masking perception

Question 41

When several tones are presented together, the ______ may be heard, even if the components in isolation are inaudible

Answer 41

complex

Question 42

Early studies suggested that the threshold depended on the ______; however, newer studies indicate that the ear is capable of integration over __________ _____ than the auditory filter

Answer 42

CB bandwidths wider

Question 43

Again, early studies showed that the threshold for detecting a narrow band of noise in the presence of 2 separated sinusoids remained _______ until the _______ rached a ____ value (presumably the CB), after which threshold decreased, but more recent studies show a less abrupt change

Answer 43

constant critical

Question 44

Can we "hear out" individual partials in a complex tone?

Answer 44

Yes, but this ability depends on many factors (including frequency resolution) one of which may be musicality

Question 45

Certainly, the frequency selectivity of the auditory system is due to the _______; but there may be a sharpening process following the BM

Answer 45

cochlea

Question 46

While the power spectrum masking model (listener uses an auditory filter centered close to the signal frequency when detecting a tone in noise) works in many situations, it does NOT work in others. In some situations, it appears that listeners make comparisons across filters

Answer 46

Comodulation masking release

Question 47

______ study: 1. Threshold for 1000 Hz tone was measured as a function of noise masker bandwidth (center freqeuncy of 1K Hz), keeping spectrum level constant 2. Two noises were used - one was random and the other was amplitude modulated 3. The patterns for the two noises were different, suggesting that subjects compare the outputs of different filters to enhance detection

Answer 47

Hall

Question 48

Profile analysis is the ability to detect a level of ________ of one component of a complex. Results suggested subjects are able to detect _-_ dB changes in the relative level of the signal, which is referred to as a detection of a change in the shape or profile of the spectrum of the sound or "profile analysis"

Answer 48

Increment 1-2 dB

Question 49

nonsimulataneous masking can occur when the masker ______ or follows the probe

Answer 49

precedes

Question 50

In forward masking, the probe ______ the masker. This is sometimes called post-__________ masking or post-_______, one of three processes which affect the threshold of a probe after another sound, the others being adaption and fatigue

Answer 50

follows post-stimulatory post-masking

Question 51

Forward masking occurs for ______ duration maskers (a few hundred milliseconds), and for signals occurring within ___ ms after masker

Answer 51

short 200

Question 52

Forward masking is greater the _______ in time the signal occurs following the masker and the amount of forward masking increases with increasing masker duration up to __ ms

Answer 52

closer 50 ms

Question 53

In backward masking, the probe _______ the masker (or masker follows probe); also referred to as pre-stimulatory masking or pre-masking. The amount of backward masking depends strongly on the _________ of subjects

Answer 53

precedes experience

Question 54

The ________ auditory system contains a bank of overlapping bandpass filters

Answer 54

peripheral

Question 55

The BM is the _____ filters, which may or may not be sharpened beyond the BM

Answer 55

initial

Question 56

When components of complex stimuli fall within _ critical band, perceptions differ from those which occur when components are spread over ______ critical bands

Answer 56

1 several

Question 57

The shape of the auditory filter is ______ on top and _______ on the sides; it is not ___________

Answer 57

round sloping rectangular

Question 58

The filter is considered a ________ function, which characterizes frequency selectivity at a particular center frequency

Answer 58

weighting

Question 59

The bandwidth of the auditory filter can be described by the _______, the value of which is __-__% of the center frequency (for normal hearers at moderate levels)

Answer 59

ERB 10-17%