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.

Acoustic Reflex Testing in Neonatal Hearing Screening and Subsequent Audiological Evaluation

2018 ◽  
Vol 61 (7) ◽  
pp. 1784-1793
Author(s):  
Lilian Cássia Bórnia Jacob-Corteletti ◽  
Eliene Silva Araújo ◽  
Josilene Luciene Duarte ◽  
Fernanda Zucki ◽  
Kátia de Freitas Alvarenga
Keyword(s):  
Risk Factors ◽  
Birth Weight ◽  
Gestational Age ◽  
Pure Tone ◽  
Broadband Noise ◽  
Acoustic Reflex ◽  
Group I ◽  
Group Ii ◽  
Gestational Age At Birth ◽  
Age At Birth

Purpose The aims of the study were to examine the acoustic reflex screening and threshold in healthy neonates and those at risk of hearing loss and to determine the effect of birth weight and gestational age on acoustic stapedial reflex (ASR). Method We assessed 18 healthy neonates (Group I) and 16 with at least 1 risk factor for hearing loss (Group II); all of them passed the transient evoked otoacoustic emission test that assessed neonatal hearing. The test battery included an acoustic reflex screening with activators of 0.5, 1, 2, and 4 kHz and broadband noise and an acoustic reflex threshold test with all of them, except for the broadband noise activator. Results In the evaluated neonates, the main risk factors were the gestational age at birth and a low birth weight; hence, these were further analyzed. The lower the gestational age at birth and birth weight, the less likely that an acoustic reflex would be elicited by pure-tone activators. This effect was significant at the frequencies of 0.5, 1, and 2 kHz for gestational age at birth and at the frequencies of 1 and 2 kHz for birth weight. When the broadband noise stimulus was used, a response was elicited in all neonates in both groups. When the pure-tone stimulus was used, the Group II showed the highest acoustic reflex thresholds and the highest percentage of cases with an absent ASR. The ASR threshold varied from 50 to 100 dB HL in both groups. Group II presented higher mean ASR thresholds than Group I, this difference being significant at frequencies of 1, 2, and 4 kHz. Conclusions Birth weight and gestational age at birth were related to the elicitation of the acoustic reflex. Neonates with these risk factors for hearing impairment were less likely to exhibit the acoustic reflex and had higher thresholds.

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.

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.

Relationship Between Loudness Discomfort Level and Acoustic Reflex Threshold for Normal and Sensorineural Hearing-Impaired Individuals

1979 ◽  
Vol 22 (4) ◽  
pp. 873-883 ◽  
Author(s):  
H. Lee McLeod ◽  
Herbert J. Greenberg
Keyword(s):  
Pure Tone ◽  
Hearing Impaired ◽  
Sensorineural Hearing ◽  
Psychophysical Method ◽  
Acoustic Reflex ◽  
Impaired Group ◽  
Group A ◽  
Reflex Threshold ◽  
Acoustic Reflex Threshold ◽  
The Relationship

The relationship between loudness discomfort level (LDL) and acoustic reflex threshold (ART) was determined by comparing the ART to the LDL obtained by the psychophysical method of constant stimuli. Randomly presented stimuli of 1000 Hz, 2000 Hz, and a multi-talker speech noise were presented to normal and sensorineural hearing-impaired listeners. The listener’s task was to judge whether the stimulus was at a level that was: (1) too loud or uncomfortably loud; or (2) not too loud or not uncomfortably loud. Prior to the judgment of the subject, the acoustic reflex threshold was determined. Both LDL and ART were found to be significantly higher for the hearing-impaired group. For the pure tone stimuli, LDL for the hearing-impaired group was at or below the ART. Significant differences were shown to exist between LDL and ART for each group. A multiple regression analysis indicated significant correlations between LDL and ART. Ranges of prediction error were selected to investigate the ability of ART to predict LDL. Both pure tone and speech ART successfully predicted LDL within ± 10 dB for a high percentage of the subjects.

The Effects of Frequency Modulation on Middle Ear Reflex

1980 ◽  
Vol 88 (3) ◽  
pp. 288-292
Author(s):  
Thomas Meeks ◽  
Laurence Owens ◽  
William Melnick
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Frequency Modulation ◽  
Pure Tone ◽  
Narrow Band ◽  
Reflex Activity ◽  
Acoustic Reflex ◽  
Fm Signals ◽  
Filtered Noise ◽  
Indirect Indication

The effect of frequency modulation on acoustic middle ear muscle reflex persistence was studied. Changes in impedance at the tympanic membrane were used as an indirect indication of reflex activity. Signals were a 2-kHz pure tone, a narrow band of noise centered at 2-kHz, and FM signals centered at 2-kHz modulated 70, 140, and 280 times per second. Acoustic reflex persistance for FM signals resembled that observed with pure-tone stimulation rather than that produced by a filtered noise.

Temporal Integration of the Contralateral Acoustic Reflex Threshold for a 1000 Hz Tonal Activator and Its Age-Related Changes

2009 ◽  
Vol 20 (04) ◽  
pp. 225-228 ◽  
Author(s):  
Michele B. Emmer ◽  
Shlomo Silman ◽  
Carol A. Silverman ◽  
Harry Levitt
Keyword(s):  
Temporal Integration ◽  
Age Effect ◽  
Broadband Noise ◽  
Hearing Level ◽  
Acoustic Reflex ◽  
Hearing Sensitivity ◽  
Age Related ◽  
Main Effect ◽  
Reflex Threshold ◽  
Acoustic Reflex Threshold

Background: Previous research has noted an age effect on the temporal integration of the acoustic reflex for a noise activator. Purpose: To determine whether the age effect earlier noted for a noise activator will be noted for a tonal activator. Research Design: Comparison of ARTs of younger and older groups at activating stimulus durations of 12, 25, 50, 100, 200, 300, 500, and 1000 msec. Study Sample: Two groups of adults with normal-hearing sensitivity: one group of 20 young adults (ten males and ten females, ages 18–29 years, with a mean age of 24 years) and one group of 20 older adults (ten males and ten females, ages 59–75 years, with a mean age of 67.5 years). Results: A significant main effect for duration was obtained. That is, as the duration increased, the acoustic reflex threshold for the 1000 Hz tonal activator decreased. The interactions of duration × age group and duration × hearing level were not significant. There was a nonsignificant main effect (p = .889) for the between-subjects factor of age. Conclusion: Results contradict the findings for broadband noise.

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.

Audiologic Findings in Hyperacusic and Nonhyperacusic Subjects

1995 ◽  
Vol 4 (1) ◽  
pp. 46-51 ◽  
Author(s):  
William T. Brandy ◽  
James M. Lynn
Keyword(s):  
Pure Tone ◽  
Growth Data ◽  
Acoustic Reflex ◽  
Adjustment Procedure ◽  
Threshold Data ◽  
Fractionation Method ◽  
Reflex Threshold ◽  
Acoustic Reflex Threshold ◽  
Loudness Growth ◽  
Male Subjects

This study compared pure-tone threshold data, acoustic reflex threshold data, and loudness growth data for a group of 25 hyperacusic male subjects vs. a group of 13 nonhyperacusic male subjects. Pure-tone thresholds and acoustic reflex thresholds were obtained in 5-dB steps, using revised Hughson-Westlake procedures. Loudness growth functions were obtained with a fractionation (method of adjustment) procedure whereby the subjects doubled loudness, using a 1-dB step attenuator. Results suggest that loudness growth was significantly different for the hyperacusic subjects compared to the nonhyperacusic subjects, but no significant differences in pure-tone thresholds or acoustic reflex thresholds were observed. When the hyperacusic group was divided into subgroups, however, the endocrine disorder subgroup had significantly lower acoustic reflex thresholds compared to the other subgroups of hyperacusic subjects. No other significant differences among the subgroups were noted.

Acoustic Reflexes in Aural Atresia Patients: Evidence of an Intact Efferent System?

2021 ◽  
pp. 000348942199016
Author(s):  
Geoffrey C. Casazza ◽  
Lincoln C. Gray ◽  
Debra Hildebrand ◽  
Bradley W. Kesser
Keyword(s):  
Surgical Repair ◽  
Acoustic Reflex ◽  
Aural Atresia ◽  
Efferent System ◽  
Academic Medical ◽  
Acoustic Reflexes ◽  
Reflex Arc ◽  
Reflex Threshold ◽  
Congenital Aural Atresia ◽  
Pure Tone Threshold

Objective: To record crossed acoustic reflex thresholds (xART’s) postoperatively from patients after surgical repair of unilateral congenital aural atresia (CAA). To seek explanations for when xARTs can and cannot be recorded. We hope to understand the implications for this central auditory reflex despite early afferent deprivation. Methods: Patients who underwent surgery to correct unilateral CAA at a tertiary academic medical were prospectively enrolled to evaluate for the presence of xART. Preoperative ARTs in the normal (non-atretic) ear, and postoperative ipsilateral ARTs (stimulus in the normal ear) and contralateral ARTs (stimulus in the newly reconstructed atretic ear; record in the normal ear) were measured at 500, 1000, and 2000 Hz. Results: Four of 11 patients with normal ipsilateral reflex thresholds preoperatively demonstrated crossed acoustic reflexes postoperatively (stimulus in reconstructed ear; record from normal ear). Four other patients demonstrated normal ipsilateral thresholds preoperatively but did not have crossed reflexes postoperatively. No reflexes (pre- or postoperatively) could be recorded in 3 patients. Crossed reflex threshold is significantly correlated with the postoperative audiometric threshold. There was no correlation between ipsilateral and contralateral reflex thresholds. Conclusion: Crossed acoustic reflexes can be recorded from some but not all postoperative atresia patients, and the thresholds for those reflexes correlate with the postoperative pure tone threshold. The presence of acoustic reflexes implies an intact CN VIII-to-opposite CN VII central reflex arc despite early unilateral sound deprivation.

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