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64 Cards in this Set
- Front
- Back
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Threshold |
basic measure in audition; minimum intensity at which a stimulus is barely audible |
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Threshold level is determined by both____________________ and ___________________ |
1. sensitivity of auditory mechanism 2. nature of stimulus used to elicit response |
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Variables affecting minimal auditory stimulus (5) |
1. acoustic parameters of signal 2. methodological variables 3. age of the listener 4. psychological factors affecting the listener 5. other factors |
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Hearing thresholds chart (tones vs dB SPL) |
Tones dB SPL 125 45 250 25.4 500 11.5 1000 7.0 2000 9.0 4000 9.5 8000 13.0 =0 dB on audiometer
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Lower Frequency Limit |
difficult to define because very low frequency stimuli cause both auditory and tactile stimulation, which are usually difficult to separate - between 10 and 30 Hz |
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Upper Frequency Limit |
hearing for frequencies up to 23,000 Hz - great deal of intensity is needed at these high frequencies to hear the tone |
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if tone used to test hearing is about ______msec or longer, duration is not a significant factor in determining minimal audible stimulus |
200 msec (1/5 sec) or longer - as stimulus duration is reduced below 200 msec, intensity needed for ear to just perceive a pure tone is increased significantly |
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The shorter the duration of the stimulus the _________ the intensity... |
greater the intensity needed to reach auditory threshold |
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Temporal integration (temporal summation) |
effect of stimulus duration on threshold level |
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Human auditory system appears to be able to summate and integrate energy over a maximal time period of approximately ______ to ______msec |
200 to 250 |
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2 methods of representing stimuli that are usually used to determine auditory threshold measurements |
1. minimal auditory field (MAF) 2. minimal audible pressure (MAP) |
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Minimal Audible Field (MAF) |
the technique in some experiments where stimuli are presented in a special room (anechoic chamber) with a controlled sound environment (Sound Field) |
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Minimal Audible Pressure (MAP) |
- measurements obtained by delivering stimuli through earphones
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What are the advantages of MAP for research and clinical purposes |
1. much easier to build adequate sound-treated room to allow earphone measurements than it is to build a properly controlled anechoic (echo free) sound field for MAF measurements 2. it is relatively simple to obtain accurate acoustic measurements in an earphone (MAP) situation |
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Hearing is approximately ____ to_____ dB _______ when measured by the MAF than MAP technique |
5-7 dB better |
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What are the 3 primary classical psychophysical methods to determine threshold? |
1. method of limits 2. Method of adjustment 3. Method of constant stimuli |
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Method of constant stimuli |
very time consuming and therefore not usually applied to clinical measures of threshold |
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Method of limits |
examiner gradually increases or decreases intensity of stimulus from audibility to inaudibility (or vice versa) and records subjects' responses |
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Method of adjustment |
subject controls intensity and sets it according to examiner's directions (ex. barely audible) |
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In audiology _____________________ procedure is used for determining pure tone thresholds |
modified method of limits |
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Hearing sensitivity decreases with age, with ____________ frequencies usually affected first and more severely |
higher |
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Hearing is most sensitive at approximately age ___________ and slowly decreases as part of physiological process of aging |
12 |
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Presbycusis (sociocusis) |
hearing loss arguably associated with aging process |
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____________ show less high-frequency hearing loss as a function of age |
females (females usually exposed to lower levels of occupational noise than males) |
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Psychological Factors within-the-subject factors influence auditory threshold |
1. subjects motivation 2. Practice 3. Listener's attention 4. Internal criterion -false positive (say they hear a tone when none is present) - instructions given by examiner |
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Other factors that may influence minimal audible signal |
- presence of environmental noise - physiological noise (blood rushing in the ear or action of middle ear muscles) - pathological conditions |
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_______ dB always equals normal hearing threshold based on ANSI standard |
0 dB HL (regardless of frequency being tested) |
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2 advantages of binaural listening rather than monaural listening |
1. localization ability 2. increased capacity to separate signal from nose (selective listening) |
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What two aspects of acoustic signal (pure tones) does the ear use in judging its origin? |
1. comparative time of arrival at the two ears 2. comparative intensity of signal at the two ears |
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If a signal arrives either _____ or ________ at one ear, it is interpreted by central auditory system as coming from that side of body |
- earlier - louder |
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Unilaterally hard-of-hearing persons frequently find difficulty in... |
selective listening in background of noise (noisy restaurants, crowded parties)
- greater problem than loss of localization ability |
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Two-ear summation effect |
hearing is approximately 3 dB more sensitive at threshold when one listens with 2 ears rather than 1 - increases to maximum of approximately 6 dB when listening at 30 dB or more sensation level |
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Right ear advantage |
appears to exist for binaurally-presented speech stimuli |
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Left ear advantage |
for non speech stimuli (ex music) |
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Difference limen (differential threshold) |
minimum change in stimulus that can be correctly judged as different from a reference stimulus in a specified fraction of trials - is smaller when two ears are used |
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Air conduction |
normal pathway of sound: from pinna (auricle) to cochlea through external auditory meatus and middle ear - signals travel through entire conductive and sensorineural mechanisms on way to central auditory mechanism |
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Bone conduction |
another pathway of sound different from air conduction; it involves applying vibration directly through the skull to cochlea in inner ear - when sound vibration is delivered by bone conduction, both cochleas (in right and left ears) are always stimulated; thus bone conduction is a form of binaural hearing - signal primarily bypasses conductive mechanism by traveling through bones of skull to inner ear |
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Clinical bone conduction |
use of mechanical vibrator coupled to skull to produce done conduction signal |
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If patient has sensorineural HL, breakdown in hearing process will occur... |
either in cochlea or along course of VIII cranial nerve (auditory nerve) from cochlea to brainstem |
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In case of conductive HL, transmission of sound will be interrupted between... |
pinna and fenestra vestibuli (oval window) |
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If both air and bone conduction thresholds are equally depressed, patient has a __________ HL |
sensorineural |
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If air conduction hearing is depressed and bone conduction hearing is normal, then patient must have a ___________ HL |
conductive |
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Audiogram |
graph of patient's air and bone conduction hearing thresholds |
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Masking |
a process in which threshold of one sound (signal) is raised by simultaneous presentation of another sound (masker) - expressed in dB - difference between signal threshold without masker present and threshold with masker present - any kind of sound can serve as masker or signal |
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cross-hearing |
the unwanted transmission of sound from one ear to the other, which may arise under certain conditions for both air and bone conduction measurements |
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Possibility of cross-hearing arises in air conduction testing when difference between ears is about ______ dB or more |
40 |
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Interaural attenuation (IA) |
insulation provided by the head between the two ears |
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The head provides IA for air-conducted sound of approximately _____ dB bone conducted sound IA = _______dB |
-40dB -0dB |
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problem of corse-hearing during audiological examination is greatly reduced via masking noise into the ________________ ear |
- better (non-test) ear |
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loudness |
subjective (psychological) perception within listener as a result of hearing auditory stimulus - perceived |
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Intensity |
a physical (acoustic) measurement of auditory stimulus that can be measured in decibels of sound pressure using sound level meter (.0002 dyne/cm 2 (Pa)) - measured |
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Pitch |
subjective (psychological) perception in listener as a result of listening to an auditory stimulus - perceived |
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Frequency |
physical (acoustic) measurement of auditory stimulus that can be measured in cycles per second (cps) or Hertz (Hz) -measured |
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10 dB rule |
- sensation of loudness will double if intensity is increased by 10 dB - if sound intensity level were reduced by 10 db, loudness perception would be halved |
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Psychological scales |
scales that try to quantify relationship between subjective sensations and physical quantities |
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Nominal Scale |
- simplest type of measurement scale - placing various scale items into different categories but no attempt is made to order them |
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Ordinal Scale |
- more complex than nominal scales because scale items are arranged in order with respect to some common feature - rank various items presented (ex 1-10)
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Interval Scale |
- differences between scale items may be numerically determined - therefore difference between scale numbers 10 and 15 represents same difference as between scale numbers 20 and 25 (also temperature) - all properties of nominal and ordinal scales, interval scales have property of additivity (equal intervals) - interval scales are NOT absolute scales (zero point) |
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Ratio Scales |
- most precise scale type - contain all properties of nominal, ordinal, and interval scales - they are also capable of: - classification (like nominal scales) - ordering (like ordinal scales) - determination of exact differences (like interval scales) - have the property of determining exact ratios between scale items - have true zero point (absolute) - (ex. ruler 8 in is twice as long as 4 in)
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Sone Scale |
- most common scale of loudness - pairs of tones are presented to each subject - "standard" is first tone in pair, standard always has the same intensity level - "comparison" is second tone; it is varied in intensity by subject - experiment begins by presenting stimulus pair to subject with 40 dB tone (1 sone) as standard - subject is instructed to adjust comparison so that it sounds twice as loud as standard - 10 dB rule in affect |
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loudness of 1 sone is arbitrarily set to be equal to loudness of... |
1000 Hz tone at 40 dB above threshold (40 dB SL) |
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"power function" |
straight line graph using logarithmic coordinates; in sone scale, loudness sensation grows as a power function of intensity |
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Mel scale |
- most common pitch scale - 1000 meals are arbitrarily set to equal pitch produced by 1000 Hz tone at 40 dB SPL - value of 1000 meals corresponds to 1000 Hz |
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Relation of pitch to frequency and loudness to intensity DOES/ DOES NOT adhere to "power law" |
DOES NOT |
