Multiple Probe Frequency Acoustic Reflex Measurements

1979 ◽  
Vol 8 (4) ◽  
pp. 233-239 ◽  
Author(s):  
M. J. Bennett ◽  
L. A. Weatherby
Keyword(s):  
Acoustic Reflex ◽  
Probe Frequency ◽  
Multiple Probe

Acoustic reflex measures at high probe frequency: a phasor diagram approach

1995 ◽  
Vol 29 (3) ◽  
pp. 144-152 ◽  
Author(s):  
Louise Reynolds ◽  
Lucille P. Morton
Keyword(s):  
Acoustic Reflex ◽  
Probe Frequency ◽  
Diagram Approach

Tympanometric and Acoustic-Reflex Studies in Neonates

1985 ◽  
Vol 28 (2) ◽  
pp. 265-272 ◽  
Author(s):  
Barbara H. Sprague ◽  
Terry L. Wiley ◽  
Robert Goldstein
Keyword(s):  
Broadband Noise ◽  
Acoustic Reflex ◽  
Probe Tone ◽  
Acoustic Reflexes ◽  
Probe Frequency ◽  
High Age ◽  
Normal Neonates ◽  
Age Change

Tympanograms and acoustic reflexes for a broadband noise and for a 1000-Hz tone were measured in normal neonates. Notched tympanograms were typical of neonatal ears for a 220-Hz probe tone. A single-peaked tympanogram was most characteristic for a probe frequency of 660 Hz. Ipsilateral and contralateral acoustic reflexes were present more frequently for a 660-Hz probe tone compared to a 220-Hz probe tone, but acoustic-reflex thresholds were not significantly different between probe tones. As with adults, acoustic-reflex thresholds for the noise were significantly lower than for the tone, and ipsilateral reflex thresholds were lower than contralateral reflex thresholds. Reliability of acoustic-reflex and tympanometric measures was high. Age change from 2 to 4 days had no significant effect on tympanometric or acoustic-reflex characteristics. There was no apparent relation between tympanometric pattern and acoustic-reflex characteristics.

Static and Dynamic Acoustic Impedance Measurements in Infant Ears

1975 ◽  
Vol 18 (3) ◽  
pp. 435-443 ◽  
Author(s):  
Robert H. Margolis ◽  
Gerald R. Popelka
Keyword(s):  
Computational Procedure ◽  
Acoustic Reflex ◽  
Mean Values ◽  
Hearing Sensitivity ◽  
Large Numbers ◽  
Threshold Data ◽  
Probe Frequency ◽  
Reflex Threshold ◽  
Computational Procedures ◽  
Acoustic Reflex Threshold

Tympanometry and acoustic reflex threshold data are reported for a series of presumably normal infants ranging in age from 55 to 132 days. In general, tympanograms displayed single peaks between ±50 mm H 2 O. Susceptance tympanograms with a 660-Hz probe frequency were sometimes characterized by monotonically increasing susceptance as ear canal pressure was changed from −200 to +200 mm H 2 O. Static values of acoustic conductance, susceptance, admittance, resistance, reactance, impedance, and phase angle were computed from tympanograms using the values of ambient and +200 mm H 2 O (0/+200 procedure) and the maximum and minimum tympanometric values (MAX/MIN procedure). Comparison of the data from the two computational procedures suggested that the MAX/MIN procedure produces means and standard deviations of static values which are more manageable for establishing confidence limits with which to evaluate potentially pathological subjects. The MAX/MIN procedure resulted in lower mean values of conductance and susceptance for infant subjects relative to previously reported adult data using a similar computational procedure. Acoustic reflex thresholds were clearly present in all testable infants at coupler sound pressure levels similar to adult data, suggesting that the relations between reflex thresholds and hearing sensitivity demonstrated in adult subjects are similarly applicable to infant subjects. Mild sedation to induce sleep without altering the reflex would make acoustic reflex threshold measurement a useful procedure for screening large numbers of infants.

scholarly journals Direction of susceptance and conductance acoustic reflexes at high probe frequencies

1994 ◽  
Vol 41 (1) ◽  
Author(s):  
Louise Reynolds ◽  
Lucille P. Morton
Keyword(s):  
Theoretical Models ◽  
Ossicular Chain ◽  
Baseline Condition ◽  
Acoustic Reflex ◽  
Low Frequencies ◽  
Transmission Properties ◽  
Intensity Range ◽  
Acoustic Reflexes ◽  
Probe Frequency

Previous investigations have shown that for low probe frequencies (220 and 660 Hz) the direction of susceptance and conductance reflexes is related to baseline transmission properties. Previously documented reflex patterns, caused by the stiffening of the ossicular chain, are characterised by decreases in both components at 220 Hz (-B-G) and increases in susceptance and decreases in conductance (+B-G) at 660 Hz. In the present study, the direction of susceptance and conductance acoustic reflexes was investigated at a probe frequency of 1000 Hz, where ears are expected to be less stiffness dominated than at the low frequencies, and for which there is little description of reflex patterns in the published literature. The pattern of ipsilateral susceptance and conductance reflexes from 30 normal ears was recorded across a wide intensity range at this probe frequency for three stimulus frequencies (0.5, 1 and 2 kHz). Reflexes were classified as either increases (+) or decreases (-) for each component, at threshold and at suprathreshold intensity levels. Ears were grouped according to transmission properties at 1000 Hz, and reflex patterns observed within each group of subjects were examined. Patterns observed in these subjects at the 1000 Hz probe frequency included: +B-G; +B+G; -B+G and -B-G. There appeared to be a relationship between baseline transmission and reflex patterns. Further, patterns appear to be consistent with theoretical models of the effect of the acoustic reflex, particularly for ears where stiffness is significant in the baseline condition. The effect of the reflex for mass dominated systems requires further investigation.

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.

Generalized Learning of Receptive and Expressive Action-Object Responses by Language-Delayed Preschoolers

1990 ◽  
Vol 55 (4) ◽  
pp. 665-678 ◽  
Author(s):  
Beth A. Mineo ◽  
Howard Goldstein
Keyword(s):  
Developmentally Delayed ◽  
Matrix Training ◽  
Lexical Knowledge ◽  
Baseline Design ◽  
Recombinative Generalization ◽  
Word Combination ◽  
Expressive Performance ◽  
Preschool Boys ◽  
Linguistic Aspect ◽  
Multiple Probe

This study examined the effectiveness of matrix-training procedures in teaching action + object utterances in both the receptive and expressive language modalities. The subjects were 4 developmentally delayed preschool boys who failed to produce spontaneous, functional two-word utterances. A multiple baseline design across responses with a multiple probe technique was employed. Subjects were taught 4–6 of 48 receptive and 48 expressive responses. Acquisition of a word combination rule was facilitated by the use of familiar lexical items, whereas subsequent acquisition of new lexical knowledge was enhanced by couching training in a previously trained word combination pattern. Although receptive knowledge was not sufficient for the demonstration of corresponding expressive performance for most of the children, only minimal expressive training was required to achieve this objective. For most matrix items, subjects responded receptively before they did so expressively. For 2 subjects, when complete receptive recombinative generalization had not been achieved, expressive training facilitated receptive responding. The results of this study elucidate benefits to training one linguistic aspect (lexical item, word combination pattern) at a time to maximize generalization in developmentally delayed preschoolers.

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