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to eight reversals, the first one is discarded and the threshold is defined as the average of the midpoints of the remaining runs. Experiments have shown that this method provides only 50% accuracy. To produce more accurate results, this simple method can be further modified by increasing the size of steps in the descending runs, e.g.
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The peak sensitivities shown in this figure are equivalent to a sound pressure amplitude in the sound wave of 10 μPa or: about -6 dB(SPL). Note that this is for monaural listening to a sound presented at the front of the listener. For sounds presented on the listening side of the head there is a rise
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detector that samples the amount of energy present within a certain time frame. A certain amount of energy is needed within a time frame to reach the threshold. This can be done by using a higher intensity for less time or by using a lower intensity for more time. Sensitivity to sound improves as the
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Method of constant stimuli has several advantages over the method of limits. Firstly, the random order of stimuli means that the correct answer cannot be predicted by the listener. Secondarily, as the tone may be absent (catch trial), "yes" is not always the correct answer. Finally, catch trials help
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Some procedures use a series of trials, with each trial using the 'single-interval "yes"/"no" paradigm'. This means that sound may be present or absent in the single interval, and the listener has to say whether they thought the stimulus was there. When the interval does not contain a stimulus, it is
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For example, suppose that the quietest sound a subject can hear is 16 dB SPL if the sound is presented at a duration of 200 ms. If the same sound is then presented for a duration of only 20 ms, the quietest sound that can now be heard by the subject goes up to 26 dB SPL. In other words, if
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consists of a series of descending and ascending trial runs and turning points (reversals). The stimulus level is increased if the subject does not respond and decreased when a response occurs. Similar to the method of limits, the stimuli are adjusted in predetermined steps. After obtaining from six
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The trial starts with the descending run, where a stimulus is presented at a level well above the expected threshold. When the subject responds correctly to the stimulus, the level of intensity of the sound is decreased by a specific amount and presented again. The same pattern is repeated until the
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Two methods can be used to measure the minimal audible stimulus and therefore the absolute threshold of hearing. Minimal audible field involves the subject sitting in a sound field and stimulus being presented via a loudspeaker. The sound level is then measured at the position of the subject's head
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Temporal summation is the relationship between stimulus duration and intensity when the presentation time is less than 1 second. Auditory sensitivity changes when the duration of a sound becomes less than 1 second. The threshold intensity decreases by about 10 dB when the duration of a tone
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To give an example, this could be the probability curve of the subject detecting a sound being presented as a function of the sound level. When the stimulus is presented to the listener one would expect that the sound would either be audible or inaudible, resulting in a 'doorstep' function. In
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Several psychophysical methods can measure absolute threshold. These vary, but certain aspects are identical. Firstly, the test defines the stimulus and specifies the manner in which the subject should respond. The test presents the sound to the listener and manipulates the stimulus level in a
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Bekesy's method contains some aspects of classical methods and staircase methods. The level of the stimulus is automatically varied at a fixed rate. The subject is asked to press a button when the stimulus is detectable. Once the button is pressed, the level is automatically decreased by the
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Two intervals are presented to a listener, one with a tone and one without a tone. The listener must decide which interval had the tone in it. The number of intervals can be increased, but this may cause problems for the listener who has to remember which interval contained the tone.
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Also this method can produce several biases. To avoid giving cues about the actual stimulus level, the dial must be unlabeled. Apart from the already mentioned anticipation and habituation, stimulus persistence (preservation) could influence the result from the method of
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for younger (18-30 year olds, red circles) and older adults (60-67 year olds, black diamonds). The hearing of older adults is shown to be significantly less sensitive than that of younger adults at frequencies of 4000 and 8000 Hz, corresponding approximately to the
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In practice this means that when measuring threshold with sounds decreasing in amplitude, the point at which the sound becomes inaudible is always lower than the point at which it returns to audibility. This phenomenon is known as the 'hysteresis effect'.
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creates completely opposite effect, and occurs when the subject becomes accustomed to responding either "yes" in the descending runs and/or "no" in the ascending runs. For this reason, thresholds are raised in ascending runs and improved in descending
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using a very small probe microphone. The two different methods produce different thresholds and minimal audible field thresholds are often 6 to 10 dB better than minimal audible pressure thresholds. It is thought that this difference is due to:
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There are several issues related to the method of limits. First is anticipation, which is caused by the subject's awareness that the turn-points determine a change in response. Anticipation produces better ascending thresholds and worse descending
901:
Miller et al., 2002. "Nonparametric relationships between single-interval and two-interval forced-choice tasks in the theory of signal detectability". Journal of
Mathematical Psychology archive. 46:4;383–417. Available from:
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Unlike the classical methods, where the pattern for changing the stimuli is preset, in adaptive methods the subject's response to the previous stimuli determines the level at which a subsequent stimulus is presented.
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physiological noises heard when ear is occluded by an earphone during minimal audible pressure measurements. When the ear is covered the subject hears body noises, such as heart beat, and these may have a masking
179:(dB) steps until the subject responds. As there are no clear margins to 'hearing' and 'not hearing', the threshold for each run is determined as the midpoint between the last audible and first inaudible level.
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hearing. With minimal audible field both ears are able to detect the stimuli but with minimal audible pressure only one ear is able to detect the stimuli. Binaural hearing is more sensitive than monaural
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However, unlike in the method of limits, here the stimulus is controlled by the listener. The subject reduces the level of the tone until it cannot be detected anymore, or increases until it can be heard
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that can just be heard by the organism. The absolute threshold is not a discrete point and is therefore classed as the point at which a sound elicits a response a specified percentage of the time.
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In the descending runs, the subject may continue to reduce the level of the sound as if the sound was still audible, even though the stimulus is already well below the actual hearing threshold.
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can be defined roughly as 'the lagging of an effect behind its cause'. When measuring hearing thresholds it is always easier for the subject to follow a tone that is audible and decreasing in
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Method of adjustment shares some features with the method of limits, but differs in others. There are descending and ascending runs and the listener knows that the stimulus is always present.
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The stimuli are presented many times at each level and the threshold is defined as the stimulus level at which the subject scored 50% correct. "Catch" trials may be included in this method.
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The stimulus level is varied continuously via a dial and the stimulus level is measured by the tester at the end. The threshold is the mean of the just audible and just inaudible levels.
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and increased when the button is not pushed. The threshold is thus tracked by the listeners, and calculated as the mean of the midpoints of the runs as recorded by the automat.
138:. Three methods are traditionally used for testing a subject's perception of a stimulus: the method of limits, the method of constant stimuli, and the method of adjustment.
77:-dependent and it has been shown that the ear's sensitivity is best at frequencies between 2 kHz and 5 kHz, where the threshold reaches as low as −9 dB SPL.
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On the other hand, you can also see in Figure 1 that our hearing is slightly more sensitive to frequencies just above 1 kHz, where thresholds can be as low as −9 dBSPL!
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with the subject not in the sound field. Minimal audible pressure involves presenting stimuli via headphones or earphones and measuring sound pressure in the subject's
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reality a grey area exists where the listener is uncertain as to whether they have actually heard the sound or not, so their responses are inconsistent, resulting in a
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Another problem may be related to step size. Too large a step compromises accuracy of the measurement as the actual threshold may be just between two stimulus levels.
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This is because 'top-down' influences mean that the subject expects to hear the sound and is, therefore, more motivated with higher levels of concentration.
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In contrast, in the ascending runs, the subject may have persistence of the absence of the stimulus until the hearing threshold is passed by certain amount.
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428:'represents the probability of a certain listener's response as a function of the magnitude of the particular sound characteristic being studied'.
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of 0.98 pW/m at 1 atmosphere and 25 °C. It is approximately the quietest sound a young human with undamaged hearing can detect at 1
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The timpani of the ear operates more as a sound pressure sensor. Also a microphone works the same way and is not sensitive to sound intensity.
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a signal is shortened by a factor of 10 then the level of that signal must be increased by as much as 10 dB to be heard by the subject.
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In the ascending run, which comes after, the stimulus is first presented well below the threshold and then gradually increased in two
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http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JASMAN00004900002B000467000001&idtype=cvips&gifs=yes
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The main disadvantage lies in the large number of trials needed to obtain the data, and therefore time required to complete the test.
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The subject's absolute hearing threshold is calculated as the mean of all obtained thresholds in both ascending and descending runs.
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Levitt H., 1971. "Transformed up-down methods in psychoacoustics". J. Acoust. Soc. Amer. 49, 467–477. Available to download from:
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Hirsh I J.,Watson C S., 1996. Auditory
Psychophysics and Perception. Annu. Rev. Psychol. 47: 461–84. Available to download from:
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predetermined pattern. The absolute threshold is defined statistically, often as an average of all obtained hearing thresholds.
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In the method of constant stimuli, the tester sets the level of stimuli and presents them at completely random order.
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Online
Hearing Threshold Test – An alternate audiometric test, with calibrated levels and results expressed in dBHL
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The 'bottom-up' theory explains that unwanted external (from the environment) and internal (e.g., heartbeat)
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and tones of b′′′′ (B7) and b′′′′′ (B8), respectively. B8 is near the high end of the piano frequency range.
88: (SPL) (the unit of 'dB(HL)' shown on the vertical axis is incorrect) are plotted from 125 to 8000
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in peak sensitivity of about 6 dB due to the increase in pressure caused by reflection from the head.
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issues and they also illustrate that the human hearing is most sensitive in the 2–5 kHz range.
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110:. The tools used to collect such information are called psychophysical methods. Through these, the
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signal duration increases up to about 200 to 300 ms, after that the threshold remains constant.
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Three Models of
Temporal Summation Evaluated Using Normal-Hearing and Hearing-Impaired Subjects
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Minimising boredom by maximising likelihood-an efficient estimation of masked thresholds
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of a physical stimulus (sound) and our psychological response to the sound is measured.
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Measurement of the absolute hearing threshold provides some basic information about our
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subject stops responding to the stimuli, at which point the descending run is finished.
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In the method of limits, the tester controls the level of the stimuli. Single-interval
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Hirsh I J.,1952. "The
Measurement of Hearing". United States of America: McGraw-Hill.
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Minimal audible field and minimal audible pressure are important when considering
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Finally, since the tone is always present, "yes" is always the correct answer.
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1001:. New York: Holt, Rinehart and Winston. Citation from the book available on:
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Classical methods date back to the 19th century and were first described by
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can hear with no other sound present. The absolute threshold relates to the
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A comparison of threshold estimation methods in children 6–11 years of age
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Katz J. (Ed). United States of
America: Lippencott, Williams & Wilkins
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http://arjournals.annualreviews.org/doi/pdf/10.1146/annurev.psych.47.1.461
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Manual of
Practical Audiometry: Volume 2 (Practical Aspects of Audiology)
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Hearing: An introduction to psychological and physiological acoustics
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Hearing an
Introduction to Psychological and Physiological Acoustics
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characterised by being 's' shaped in its graphical representation.
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The threshold of hearing is generally reported in reference to the
583:. Second Edition. United States of America: Williams & Wilkins
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Descending runs give better hearing thresholds than ascending runs
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Psychometric
Functions for Children's Detection of Tones in Noise
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Series of descending and ascending trials runs and turning points
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The trial uses several series of descending and ascending runs.
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Equal loudness contours and audiometry – Test your own hearing
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results in the subject only responding to the sound if the
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Series of descending and ascending runs in Method of Limits
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617:. Fourth edition. United States of America: Marcel Dekker
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The subject responds "yes"/"no" after each presentation.
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846:"24/192 Music Downloads ...and why they make no sense"
750:. 2nd edition. New York and Basel: Marcel Dekker, Inc.
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can be converted to plane wave sound intensity using
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than to detect a tone that was previously inaudible.
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The subject reduces or increase the level of the tone
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Subject responding "yes"/"no" after each presentation
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The very quietest perceptible sound is about -8dbSPL
1038:
A Concise
Vocabulary of Audiology and allied topics
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Psychometric function of absolute hearing threshold
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232:Thus, there are no ascending or descending trials.
16:Minimum sound level that an average human can hear
447:Minimal audible field vs minimal audible pressure
159:paradigm' is used, but there are no catch trials.
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904:http://portal.acm.org/citation.cfm?id=634580
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782:. University College London. Archived from
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367:The threshold being tracked by the listener
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1120:Threshold of Hearing – equation and graph
1105:The psychoacoustics of multichannel audio
1090:Reference levels for objective audiometry
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684:{\displaystyle I={\frac {p^{2}}{\rho v}}}
65:, i.e. 0 dB SPL, corresponding to a
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43:that an average human ear with normal
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816:College of Santa Fe Auditory Theory
775:Jones, Pete R (November 20, 2014).
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764:(third ed.). Wiley-Blackwell.
579:Durrant J D., Lovrinic J H. 1984.
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1075:On Minimum Audible Sound Fields
1065:Fundamentals of psychoacoustics
968:. Chichester: Whurr Publishers.
762:Acoustic and Auditory Phonetics
439:The psychometric function is a
1095:Response bias in psychophysics
1050:Fundamental aspects of hearing
986:Handbook of Clinical Audiology
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84:Average hearing thresholds in
73:. The threshold of hearing is
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21:absolute threshold of hearing
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1021:. Accessed 28 February 2007
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330:Staircase (up-down) methods
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1015:. (Accessed 1 March 2007).
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413:is above a certain point.
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301:Modified classical methods
215:Method of constant stimuli
29:absolute hearing threshold
1019:www.thefreedictionary.com
999:Elements of psychophysics
844:Montgomery, Christopher.
581:Bases of Hearing Sciences
136:Elements of Psychophysics
1100:Sensitivity of Human Ear
906:. Accessed 1 March 2007.
892:. Accessed 1 March 2007.
812:"Lecture 007 Hearing II"
359:Bekesy's tracking method
122:called a "catch trial".
760:Johnson, Keith (2015).
547:Signal detection theory
494:The ear operates as an
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27:), also known as the
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307:Pure tone audiometry
257:Method of adjustment
997:Fechner, G., 1860.
964:Arlinger, S. 1991.
810:Feilding, Charles.
626:RMS sound pressure
353:3-down-1-up methods
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925:J. Acoust. Soc. Am
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747:
692:
622:
614:
580:
501:
493:
489:
485:
473:
461:monaural vs
450:
438:
430:
424:
415:
404:
401:
391:
370:
352:
348:
343:
341:
324:
315:
256:
214:
156:
150:
135:
134:in his work
129:
120:
116:
105:
63:micropascals
53:
32:
28:
24:
20:
18:
476:calibration
342:The simple
286:adjustment.
196:Habituation
190:thresholds.
37:sound level
1129:Categories
860:2016-03-17
826:2016-03-17
793:2016-03-16
558:References
393:Hysteresis
374:attenuator
112:perception
95:piano keys
1135:Acoustics
1115:Threshold
673:ρ
454:ear canal
397:amplitude
75:frequency
41:pure tone
1041:Archived
850:xiph.org
691:, where
527:Loudness
506:See also
466:hearing/
463:binaural
86:decibels
1140:Hearing
950:1 March
945:5541744
715:is the
470:effect.
177:decibel
45:hearing
943:
496:energy
275:again.
157:yes/no
61:of 20
787:(PDF)
780:(PDF)
512:dB(A)
407:noise
199:runs.
49:sound
39:of a
952:2007
941:PMID
552:Sone
532:Phon
19:The
984:IN
933:doi
71:kHz
56:RMS
31:or
25:ATH
1131::
973:^
939:.
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927:.
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911:^
872:^
863:.
848:.
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814:.
796:.
723:^
588:^
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436:.
355:.
351:,
90:Hz
1005:.
954:.
935::
703:v
693:ρ
676:v
667:2
663:p
657:=
654:I
634:p
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