Quiz 2

Question 1

Signals are always detected in background of _____, which varies _______

Answer 1

noise
randomly

Question 2

The separation between the two distributions is a measure of _______ known as _______

Answer 2

sensitivity
d prime

Question 3

Many non-sensory variables affect detection, including
1.
2.
The influence of these non-sensory factors is called _____ ______

Answer 3

1. probability of stimulus occurrence
   Consequences of response

Response vias

Question 4

When a subject has a high expectation of stimulus occurrence, the probability of saying “yes” is _______-p

Answer 4

increased

Question 5

What are the four outcomes ?

Answer 5

Hit (yes when stimulus is presented)

Miss (no, when stimulus is presented)

False alarm ( yes, when no stimulus present)

Correct rejection (no, when no stimulus present)

Question 6

ROC is the relationship between the probability of “___” when stimulus is present (hit rate) and “___” when stimulus is absent (false alarm rate) this is plotted on a chart called ________ _______ _______

Answer 6

yes
yes

receiver operating characteristic

Question 7

The ROC curve shows how _____ rate changes as a function of changed in the ______ _____ rate

Answer 7

hit

false alarm

Question 8

Each ROC curve is a ______ stimulus intensity

Answer 8

single

Question 9

“______” for detections will influence responses

Answer 9

Payoffs

Question 10

I the payoff for correct detection is high, subject will say “___” frequently and the hit rate and false alarm rate will ______

If the payoff for correct rejections and the hit and false alarm rate will _______

Answer 10

yes
increase
decrease

Question 11

An ROC curve can be created by changing the _______ and ______ of detection while maintaining stimulus intensity and probability

Answer 11

values
costs

Question 12

The combinations of costs and values will produce the _____ on the ROC curve for a given stimulus intensity

Answer 12

points

Question 13

As the separation between the N and SN distributions increases (detectability increases) the ROC curve _______ more rapidly

Answer 13

rises

Question 14

Controlling response bias can be done through ________ training of subjects, but is often accomplished through the use of “______ _____” in which no stimuli are presented

Answer 14

systematic
catch trials

Question 15

In TSD, subjects make a decision about whether the sample can from the _ distribution or the __ distribution, based on a _________ ratio

Answer 15

N
SN
likelihood

Question 16

When the likelihood ratio exceeds 1.0, it is more likely that the sample came from the __ distribution and when <1.0 is more likely that sample came from the _ distribution

Answer 16

SN
N

Question 17

TSD criterion assumes that the observer sets a particular likelihood ratio as a criterion (β), as that when the sample is at or above β, the observer chooses __ (and vice-versa_

Answer 17

SN

Question 18

High (strict not to much yesing) criteria will _______ false alarms and ______ correct rejections while low criteria will ______ misses and _____ hits

Answer 18

minimize x2
maximize x2

Question 19

The optimal criterion depends on the ________ probabilities and the _____ and _____ of response

Answer 19

stimulus
costs
values

Question 20

The finding that threshold measure are affected by changes in the _______ criterion throws _____ on the viability of the classical procedures

Answer 20

listeners
doubt

Question 21

The methods of TSD attempt to independently measure ________ and ______ ______

Answer 21

sensitivity
criterion location

Question 22

TSD asserts that d prime is equal to the difference of the ______ of the __ and _ distributions divided by the _______ ______ of the N distribution

Answer 22

difference
N
SN
standard deviation

Question 23

d’ can be determined from the _______ ______ and _____ rates

Answer 23

false alarm
hit

Question 24

The criterion location on the noise distributions is determined by subtracting the _______ of _____ ______

Answer 24

probability
false alarms

1.0 - p (FA) = ZN (z score)

Question 25

The location on the SN distribution is 1.0 - _ (_) = ZSN also d' = ZN - ZSN

Answer 25

p (H)

Question 26

Once the ROC curve is determined, the listener's criterion can be found, if the point is at the bottom of the curve, the criterion is ____ and if the point is at the top of the curve the criterion is _____

Answer 26

high low

Question 27

The ordinate of the N distribution at criterion is the ordinate value (O) corresponding to 1.0 - __

Answer 27

FA

Question 28

The ordinate of the SN distribution is the ordinate value corresponding to 1.0 - _

Answer 28

H

Question 29

Criterion (β) is O subSN/O subN (β) Beta value is at 1 where the coordinated cross (more than 1 moving to _____ less than 1 is moving to the _____)

Answer 29

right left

Question 30

Calculating d' and β is a way to examine the effects of a variable on _______ and/or criterion and a way to examine the outcomes of different experimental conditions.

Answer 30

detectability

Question 31

Ex. given a d’ of 1, what is the probability of a false alarm if the probability of hits is a .5

Answer 31

.15

Question 32

Given a d’ of 2, what is the probability of a correct rejection if the probability of a hit is .5?

Answer 32

.02

Question 33

You have tested the hearing of an individual whose hit and false alarm rates are .84 and .18 respectively. Assuming that the N and SN distributions are normal with equal variance, calculate the d’, B, C’ for this person and explain what each number means

Answer 33

Method A 1-.18 = .82 then find Z value on chart which is Zn= .92 - -.99(Zsn) = high d’ 1.921

Question 34

What are the TSD procedures? which one is important in psychoacoustics*

Answer 34

Yes-No Forced choice* Confidence rating Same-Different Adaptive methods: Forced -choice tracking Up-down transformed response Pest Maximum-likelihood

Question 35

Yes-No describe

Answer 35

-Long series of SN and N trials are conducted (with a stated proportion of SN and stated values and costs for each session) -Payoffs and signal probabilities are constant for a session -Experimental data for different signal probabilities and payoffs yield expected ROC curves, and measurements of sensitivity are stable under all conditions -If only 1 session is conducted, the value of d’ and β can be estimated *but an ROC curve cannot be plotted.

Question 36

Forced Choice

Answer 36

-This method is unaffected by changes in criterion. -For each trial, 2 or more intervals are presented and the observer reports which interval contained the signal. -The proportion of correct responses—p (C)— is converted to d’ from a table (depending on the number of intervals involved). -Forced-choice procedures are also useful in measuring difference thresholds.

Question 37

Confidence Rating?

Answer 37

-This method is very efficient for collecting data in a single session. -The observer makes a confidence rating for each yes-no judgment made (e.g., 5 if very sure, 4 if fairly sure, etc.). -Proportions of responses for each rating are determined and an ROC curve is derived (see handout).

Question 38

Same - Different?

Answer 38

-As the name states, the observer’s task in this procedure is to report whether two stimuli in a trial are the same or different. In a discrimination of A and B, there are, therefore, 4 possible outcomes on each trial—2 same (AA, BB) and 2 different (AB, BA). -The hit rate is the proportion of “different” responses when the stimuli differ, and the false alarm rate is the proportion of “different” responses when the stimuli are the same; d’ calculated from these, although some adjustments may have to be made, depending on the decision rule used by the subject. -Same-different can also be used to measure the difference threshold.

Question 39

Oddity?

Answer 39

-In this procedure, the observer is asked to discriminate between different stimuli. -There are 3 or more intervals with one stimulus in all but one of the intervals and the other stimulus in the remaining interval. -d’ depends on p (c), and is determined through the use of a table.

Question 40

The threshold is a "_____" meaning the _____ stimulus level that elicits a response on a specified proportion of presentations ___% is a typical performance criterion

Answer 40

statistic lowest 50%

Question 41

minimum audibility curves assess _____ ______ (detectability) for a large number of young, otologically normal listeners across the range of audible frequencies in the free field and under earphones

Answer 41

absolute thesholds

Question 42

Minimum audibility curves plot the obtained ______ (central tendencies) on a graph to obtain the _______ audbility curve

Answer 42

thehsolds minimum

Question 43

Lower frequency limit of audibility is usually defined as __ Hz responses < __ Hz require _____ intensity levels, are not described as _____ and are more ______ than ______

Answer 43

20 20 high tonal tactile auditory

Question 44

Upper frequency limit is defined as __K Hz, since higher frequencies elicit a tactile sensation

Answer 44

20

Question 45

"best" sensitivity is senn in the _____ Hz to _______ Hz region

Answer 45

2000 - 5000

Question 46

From 500 to 5000 Hz, sensitivity is around __ dB SPL

Answer 46

10

Question 47

Below 500 Hz and above 5000 Hz, hearing becomes increasingly ____ sensitive, reflecting the transmission characteristics of the __ (and __)

Answer 47

less Me OE

Question 48

Conditions under which thresholds are obtained influence results: (6)

Answer 48

Ambient Noise Method Subjects Calibration / Transducer type Sound field (MAF) Earphones (MAP)

Question 49

What are the two methods of measurement for minimum audibility

Answer 49

Minimum audible field (MAF) -Sound-treated or anechoic chamber with listener seated 1m at 00 azimuth from speaker -Measurement made after listener removed, with microphone at center of head Minimim audible pressure (MAP) -MAP/MAP-C -Measurement made using probe mic in EAM (close to TM) or coupler; sound usually delivered via earphone

Question 50

Which is more sensitive MAF or MAP

Answer 50

MAF is slightly more sensitive -MAF is a binaural measure -MAP influenced by masking effects of physiological and other noise -Head and body diffraction effects -Differences in how measurements are made

Question 51

Intense sound (130 dB SPL) of any frequency will elicit a _______ sensation, which is called the "_______ of ______"

Answer 51

tactile threshold of feeling

Question 52

Further increase in intensity elicit a ______ sensation (140 dB SPL), this threshold is also known as the "_______ threshold" and it does not cary with frequency

Answer 52

pain terminal

Question 53

The area between minimum audbility curve and threshold of feeling is called the ______ _____ area

Answer 53

auditory response area OR Dynamic range of hearing

Question 54

As duration decreases below about ____ ms (critical duration), power must be _______ for detection to occur (______ = ______ / _____)

Answer 54

200 increased Power = Energy / Time

Question 55

For each 10-fold decrease in time (below about 200 ms), a __ dB increase in level is needed, and for each 2-fold decrease in time (<200 ms) a _ dB increase is needed

Answer 55

10 dB 3 dB

Question 56

Integrating the power of a tonal signal takes place over approximately ____-___ ms; differs for other stimuli

Answer 56

200-300

Question 57

Temporal integration thresholds improves with a _______ stimulus because the increased time provides more opportunities to detect the stimulus through repeated sampling

Answer 57

longer

Question 58

Temporal resolution is the ________ detectable _____ separation between signals

Answer 58

smallest time

Question 59

The ability to resolve fine temporal differences is critical for ______ ______. A common method of assessing this is through ____ detection threshold tests

Answer 59

speech recognition gap