Acoustic-Reflex Growth and Loudness

1979 ◽  
Vol 22 (2) ◽  
pp. 295-310 ◽  
Author(s):  
Michael G. Block ◽  
Terry L. Wiley
Keyword(s):  
Acoustic Impedance ◽  
Dynamic Range ◽  
Broadband Noise ◽  
Reflex Response ◽  
Impedance Change ◽  
Acoustic Reflex ◽  
Growth Functions ◽  
The Mean ◽  
Standard Deviations ◽  
The Individual

Acoustic-reflex growth functions and loudness-balance judgments were obtained for three normal-hearing subjects with normal middle-ear function. The hypothesis that acoustic reflex-activating signals producing proportionately equal acoustic-impedance changes are judged equal in loudness was evaluated. The mean acoustic impedance and associated standard deviations were computed for the baseline (static) and activator (reflex) portions of each reflex event. An acoustic-impedance change exceeding two standard deviations of baseline was defined as the criterion acoustic-reflex response. Acoustic impedance was measured as a function of activator SPL for broadband noise and a 1000-Hz tone from criterion magnitude to the maximum acoustic impedance (or 120-dB SPL). This was defined as the dynamic range of reflex growth. Loudness-balance measurements were made for the 1000-Hz tone and broadband noise at SPL’s representing 30, 50, and 70% of the individual dynamic range. The data supported the hypothesis.

Acoustic-Reflex Dynamics and the Loudness-Discomfort Level

1985 ◽  
Vol 50 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Donna G. Greenfield ◽  
Terry L. Wiley ◽  
Michael G. Block
Keyword(s):  
Acoustic Impedance ◽  
Normal Hearing ◽  
Broadband Noise ◽  
Impedance Change ◽  
Acoustic Reflex ◽  
Good Reliability ◽  
Large Variability ◽  
Growth Functions ◽  
Within Subjects ◽  
Relative Change

Acoustic-reflex growth functions and Loudness-Discomfort Level (LDL) measures were obtained for 15 normal-hearing subjects. The hypothesis that signals considered uncomfortably loud occur at intensity levels that produce proportionately equal acoustic-reflex magnitudes was evaluated. Individual reflex growth functions were measured as a function of activator SPL for a 1000-Hz tone, a 4000-Hz tone, and a broadband noise. These growth functions were measured within subjects (two trials) and across subjects in terms of (a) percentage acoustic-impedance change at LDL, (b) percentage acoustic-reactance change at LDL, (c) acoustic impedance at LDL, (d) relative change in acoustic impedance at LDL, and (e) ratio of static acoustic impedance to change in acoustic impedance at LDL. Although the loudness and acoustic-reflex measures demonstrated good reliability across trials, the data showed large variability across subjects and did not support the experimental hypothesis. It was concluded, therefore, that the use of acoustic-reflex measures in the estimation of an individual's LDL is unwarranted.

Acoustic-Reflex Dynamics for Pulsed Signals

1978 ◽  
Vol 21 (2) ◽  
pp. 295-308
Author(s):  
Terry L. Wiley ◽  
Raymond S. Karlovich
Keyword(s):  
Duty Cycle ◽  
Acoustic Impedance ◽  
Normal Hearing ◽  
Broadband Noise ◽  
Threshold Shift ◽  
Temporary Threshold Shift ◽  
Acoustic Reflex ◽  
Stapedius Muscle ◽  
Duty Cycles

Contralateral acoustic-reflex measurements were taken for 10 normal-hearing subjects using a pulsed broadband noise as the reflex-activating signal. Acoustic impedance was measured at selected times during the on (response maximum) and off (response minimum) portions of the pulsed activator over a 2-min interval as a function of activator period and duty cycle. Major findings were that response maxima increased as a function of time for longer duty cycles and that response minima increased as a function of time for all duty cycles. It is hypothesized that these findings are attributable to the recovery characteristics of the stapedius muscle. An explanation of portions of the results from previous temporary threshold shift experiments on the basis of acoustic-reflex dynamics is proposed.

scholarly journals Acoustic reflex measurements and the loudness function in sensorineural hearing loss

1980 ◽  
Vol 27 (1) ◽  
Author(s):  
Sheila Uliel
Keyword(s):  
Hearing Loss ◽  
Differential Diagnosis ◽  
Sensorineural Hearing Loss ◽  
Acoustic Impedance ◽  
Pure Tone ◽  
Sensorineural Hearing ◽  
Acoustic Reflex ◽  
Reflex Responses ◽  
Loudness Function ◽  
The Individual

The suprathreshold acoustic reflex responses of forty two ears affected by sensorineural hearing loss of cochlear origin and fifty-eight ears demonstrating normal hearing, were recorded by means of an electro-acoustic impedance meter and attached X-Y recorder. The recordings were done in ascending and descending fashion,  at successively increasing and decreasing 5dB intensity levels from 90-120-90 dB HL respectively, for the individual pure-tone frequencies of 500, 1 000, 2 000 and 4 000 Hz. The contralateral mode of measurement was employed. Analysis of  these recordings indicated that the acoustic reflex  responses could be differentiated into five  characteristic patterns of  growth, which could be depicted upon a continuum of peaked, peaked-rounded, rounded, rounded-flat,  and flat  shapes. The peaked and peaked-rounded patterns were found  to predominate at all four pure-tone frequencies  in the normal ears, while the rounded-fiat  and flat  patterns were found  to predominate only at the higher pure-tone frequencies of 2 000 and 4 000 Hz in the ears affected  by sensorineural hearing loss. This latter relationship was also able to be applied to two disorders of  the loudness functio— loudness recruitment and hyperacusis. It was concluded that the flattened  acoustic reflex  patterns at the higher pure-tone frequencies  constituted a potential diagnostic cue related to the differential  diagnosis of sensorineural hearing loss, and to disorders of  the loudness function.

Newborn Acoustic Reflexes to Noise and Pure-Tone Signals

1982 ◽  
Vol 25 (3) ◽  
pp. 383-387 ◽  
Author(s):  
Michael J. Bennett ◽  
Lynn A. Weatherby
Keyword(s):  
Pure Tone ◽  
Broadband Noise ◽  
Acoustic Reflex ◽  
Acoustic Reflexes ◽  
Auditory Response ◽  
Reflex Activation ◽  
The Mean ◽  
Reflex Threshold ◽  
Filtered Noise ◽  
High Pass

A variable-frequency probe-tone acoustic-impedance bridge has been developed to enable an artifact-free pure-tone acoustic reflex study to be carried out on neonates. Contralateral reflex thresholds for pure tones, broadband noise, and filtered noise were measured in 28 newborns aged 4–8 days. The mean reflex threshold for the broadband noise was 73 dB SPL, 4 dB lower than the reflex threshold for the 2600-Hz low- and high-pass noise bands. Reflex activation at 500, 1000, 2000, and 4000 Hz gave responses that closely followed the normal adult pattern although reflex thresholds were approximately 10 dB higher. Two infants failed to demonstrate reflexes. One of these failed a behavioral-response test using the Auditory Response Cradle and was found to have mild jaundice. The second infant passed the behavioral test and had measurable reflexes 5 weeks later. A third baby with elevated reflex thresholds also was jaundiced but had normal behavioral responses and was discharged. Discussion of these results emphasizes their value to those engaged in neonatal auditory assessment.

The Effects of Aging on the Magnitude of the Acoustic Reflex

1981 ◽  
Vol 24 (3) ◽  
pp. 406-414 ◽  
Author(s):  
Richard H. Wilson
Keyword(s):  
Sound Pressure ◽  
Age Groups ◽  
Sampling Technique ◽  
Pressure Level ◽  
Broadband Noise ◽  
Individual Growth ◽  
Growth Data ◽  
Ear Canal ◽  
Acoustic Reflex ◽  
The Individual

Aural acoustic-immittance (admittance and impedance) measurements during the quiescent and reflexive states were made using a computer sampling technique on 18 subjects with normal hearing in each of two age groups (< 30 years and > 50 years). Seven pure-tones (250–6000 Hz) and broadband-noise stimuli served to elicit the acoustic reflex at sound-pressure levels from 84–116 dB (tones) and 66–116 dB (noise) in 2-dB steps during ascending and descending runs. The contralateral middle-ear activity, was monitored with a 220-Hz probe by digitizing the conductance and susceptance outputs of an acoustic-admittance meter. The computer corrected for the immittance characteristics of the ear-canal volume by utilizing measurements made at an ear-canal pressure of -350 daPa and then by converting the conductance and susceptance values into admittance and impedance units. The results are reported as the immittance change between the quiescent and reflexive states as a function of both the activator sound-pressure level and the activator-pressure level above the reflex threshold. There were no significant differences between the static-immittance values for the two groups, Although acoustic-reflex thresholds for the two groups were the same in the low- to mid-frequency region (250–2000 Hz), the reflex thresholds for the > 50-years group were elevated significantly ( 8 dB) for 4000 Hz, 6000 Hz, and noise activators. In all conditions, the magnitude of the acoustic reflex was substantially smaller for the > 50-years group as compared with the < 30-years group. The variability of the reflex magnitude was large for both groups of subjects. Saturation of the individual growth functions, which was frequency dependent, occurred twice as often with the > 50-years group as with the < 30-years group. The relationship between the magnitude changes in conductance and susceptance from the quiescent to the reflexive state was the same for the two groups. Finally, the magnitude differences among the reflex-growth data were not related to differences in static immittance.

The Meaninglessness of the Mean

2018 ◽  
pp. 98-107
Author(s):  
Erwin B. Montgomery
Keyword(s):  
Infinite Number ◽  
Probability Function ◽  
Central Tendency ◽  
Ontological Status ◽  
Cumulative Percentage ◽  
The Mean ◽  
Standard Deviations ◽  
Arbitrary Collection ◽  
The Individual

The mean (average) or other central tendencies of a set of data is an internal construct that does not necessarily reflect reality. It is possible to determine the central tendency from any arbitrary collection of data as long as they vary on the same dimension. Even if applied to a relevant sample of data, the central tendency may be a poor reflection of data. A virtually infinite number of different collections of data may have the same central tendency and variance. This has very important implications when reasoning from studies reporting means and standard deviations. The same concerns apply to medians as the central tendencies and quartiles as the variability. When translating studies to the individual patient, the cumulative percentage (probability) function may be more helpful. There is a strong inclination to attribute some ontological status (reality) to measures of central tendency that can be misleading.

Aural Acoustic-Immittance Measurements

1981 ◽  
Vol 46 (4) ◽  
pp. 413-421 ◽  
Author(s):  
Richard H. Wilson ◽  
Janet E. Shanks ◽  
Therese M. Velde
Keyword(s):  
Sound Pressure ◽  
Broadband Noise ◽  
Intensity Level ◽  
Growth Data ◽  
Acoustic Reflex ◽  
Individual Subject ◽  
Acoustic Admittance ◽  
Sound Pressure Levels ◽  
Pure Tones ◽  
The Individual

Bilateral measurements of the aural acoustic-immittance characteristics of the middle-ear transmission systems of 48 subjects were made with an acoustic-admittance meter. The measurements, including static acoustic-immittance, acoustic-reflex thresholds, and acoustic-reflex growth functions, were made using a 220-Hz probe. The contralateral reflex data for three pure tones (500, 1000, and 2000 Hz) and for broadband noise were acquired in 2-dB steps at sound-pressure levels from 84–116 dB (tones) and 66–116 dB (noise) during ascending- and descending-intensity level runs. For all acoustic-immittance measurements, right ear and left ear comparisons were made and found not to be significantly different. The individual subject data then were expressed as the absolute differences between ears. In this manner normative inter-aural immittance differences were defined. The peak static immittance data were analyzed in terms of median inter-aural differences and upper 80% cut-off values. The 80% range for normal immittance values were smaller for a within subject versus an across subject comparison. For acoustic-reflex thresholds, a disparity between ears of >10 dB was suggested as indicative of an abnormality in the auditory mechanism. Finally, the reflex-growth data indicated mean inter-aural absolute differences that ranged to .040–.043 acoustic mmhos (300–400 acoustic ohms) at the higher reflex activator sound-pressure levels.

Validation of the SunTech Medical Advantage Model 2 Series Automated Blood Pressure Module in Pregnancy

2018 ◽  
Vol 36 (01) ◽  
pp. 067-073
Author(s):  
Kristin Dotson ◽  
Sarah Anderson ◽  
Stacy Harris ◽  
Lorie Harper ◽  
Alan Tita ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Test Device ◽  
Urine Protein ◽  
Noninvasive Blood Pressure ◽  
The Mean ◽  
Standard Deviations ◽  
The Individual ◽  
In Pregnancy ◽  
Mercury Sphygmomanometer

Objective We sought to validate the SunTech Medical Advantage Model 2 Series with firmware LX 3.40.8 algorithm noninvasive blood pressure module in a pregnant population, including those with preeclampsia. Study Design Validation study of an oscillometric noninvasive blood pressure module using the ANSI/AAMI ISO 81060-2:2013 standard guidelines. Pregnant women were enrolled into three subgroups: normotensive, hypertensive without proteinuria, and preeclampsia (hypertensive with random protein-to-creatinine ratio ≥ 0.3 or a 24-hour urine protein > 300 mg). Two trained research nurses, blinded to each other's measurements, used a mercury sphygmomanometer to validate the module by following the protocol set forth in the ANSI/AAMI ISO 81060-2:2013 standard guidelines. Results A total of 45 patients, 15 in each subgroup, were included. The mean systolic and diastolic differences with standard deviations between the module and the mean observers' measurements for all participants were −2.3 ± 7.3 and 0.2 ± 6.5 mm Hg, respectively. The systolic and diastolic standard deviations of the mean of the individual patient's paired module and observers' measurements were 6.27 and 5.98 mm Hg, respectively. The test device, relative to a mercury sphygmomanometer, underestimated the systolic blood pressure in patients with preeclampsia by at least 10 mm Hg in 24% (11/45) of paired measurements. Conclusion The SunTech Medical Advantage Model 2 Series with firmware LX 3.40.8 algorithm noninvasive blood pressure module is validated in pregnancy, including patients with preeclampsia; however, it may underestimate systolic blood pressure measurements in patients with preeclampsia.

Intrasubject Variability in Power Reflectance

2014 ◽  
Vol 25 (05) ◽  
pp. 441-448 ◽  
Author(s):  
Defne Abur ◽  
Nicholas J. Horton ◽  
Susan E. Voss
Keyword(s):  
Standard Deviation ◽  
Repeated Measurements ◽  
Ear Canal ◽  
Mean Power ◽  
Deep Insertion ◽  
Left And Right ◽  
The Mean ◽  
Standard Deviations ◽  
The Individual ◽  
The Right

Background: Power reflectance measurements are an active area of research related to the development of noninvasive middle-ear assessment methods. There are limited data related to test-retest measures of power reflectance. Purpose: This study investigates test-retest features of power reflectance, including comparisons of intrasubject versus intersubject variability and how ear-canal measurement location affects measurements. Research Design: Repeated measurements of power reflectance were made at about weekly intervals. The subjects returned for four to eight sessions. Measurements were made at three ear-canal locations: a deep insertion depth (with a foam plug flush at the entrance to the ear canal) and both 3 and 6 mm more lateral to this deep insertion. Study Sample: Repeated measurements on seven subjects are reported. All subjects were female, between 19 and 22 yr old, and enrolled at an undergraduate women’s college. Data Collection and Analysis: Measurements on both the right and left ears were made at three ear-canal locations during each of four to eight measurement sessions. Random-effects regression models were used for the analysis to account for repeated measures within subjects. The mean power reflectance for each position over all sessions was calculated for each subject. Results: The comparison of power reflectance from the left and right ears of an individual subject varied greatly over the seven subjects; the difference between the power reflectance measured on the left and that measured on the right was compared at 248 frequencies, and depending on the subject, the percentage of tested frequencies for which the left and right ears differed significantly ranged from 10% to 93% (some with left values greater than right values and others with the opposite pattern). Although the individual subjects showed left-right differences, the overall population generally did not show significant differences between the left and right ears. The mean power reflectance for each measurement position over all sessions depended on the location of the probe in the ear for frequencies of less than 1000 Hz. The standard deviation between subjects' mean power reflectance after controlling for ear (left or right) was found to be greater than the standard deviation within the individual subject’s mean power reflectance. The intrasubject standard deviation in power reflectance was smallest at the deepest insertion depths. Conclusions: All subjects had differences in power reflectance between their left and right ears at some frequencies; the percentage of frequencies at which differences occurred varied greatly across subjects. The intrasubject standard deviations were smallest for the deepest probe insertion depths, suggesting clinical measurements should be made with as deep an insertion as practically possible to minimize variability. This deep insertion will reduce both acoustic leaks and the effect of low-frequency ear-canal losses. The within-subject standard deviations were about half the magnitude of the overall standard deviations, quantifying the extent of intrasubject versus intersubject variability.

Acoustic-Reflex Adaptation

1984 ◽  
Vol 27 (4) ◽  
pp. 586-595 ◽  
Author(s):  
Richard H. Wilson ◽  
June K. McCullough ◽  
David J. Lilly
Keyword(s):  
Half Life ◽  
Onset Time ◽  
Life Time ◽  
Broadband Noise ◽  
Acoustic Reflex ◽  
Individual Subject ◽  
Baseline Drift ◽  
Reflex Threshold ◽  
The Individual ◽  
Life Function

Acoustic-reflex adaptation was studied in 35 subjects with normal hearing using nine pure-tone activators (250-6000 Hz) and a broadband-noise activator. The individual subject data generated by the 31-s activators presented 10 dB above the reflex threshold were digitized, corrected for baseline drift and ear Canal volume, and analyzed in terms of the acoustic-admittance change in acoustic mmhos and in terms of the percentage of maximum-reflex magnitude. Reflex adaptation increased as a function of frequency. The adaptation functions for the lower frequencies (⩽1500 Hz) were essentially linear over the 31-s activator period, whereas the functions for the higher frequencies (⩾2000 Hz) were curvilinear over the activator period. The experimental half-tile data are compared with a theoretical half-life function that was generated to estimate normal acoustic-reflex adaptation as a function of activator frequency. Finally, the means and standard deviations are reported and discussed for (a) the onset time of adaptation; (b) the half-life time, and (c) the percentage of maximum reflex magnitude at 5-s intervals from 5 to 30 s.

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