Fast Click Rate Electrocochleography and Auditory Brainstem Response in Normal-Hearing Adults Using Continuous Loop Averaging Deconvolution.

OBJECTIVES: Using the continuous loop averaging deconvolution (CLAD) technique for conventional electrocochleography (ECochG) and auditory brainstem response (ABR) recordings, the effects of testing at high stimulus rates may have the potential to diagnose disorders of the inner ear and auditory nerve. First, a body of normative data using the CLAD technique must be established. DESIGN: Extratympanic click ECochG and ABR to seven stimulus rates using CLAD were measured simultaneously from a tympanic membrane electrode and surface electrodes on the forehead and mastoid of 42 healthy individuals. RESULTS: Results showed that the compound action potential (AP) of the ECochG and waves I, III, and V of the ABR decreased in amplitude and increased in latency as stimulus rate was increased from standard 7.1 clicks/s up to 507.81 clicks/s, with sharp reduction in AP amplitude at 97.66 clicks/s and reaching asymptote at 292.97 clicks/s. The summating potential (SP) of the ECochG, however, stayed relatively stable, resulting in increased SP/AP ratios with increasing rate. The SP/AP amplitude ratio showed more stability than AP amplitude findings, thus it is recommended for use in evaluation of cochlear and neural response. CONCLUSIONS: Results of both amplitude and latency data from this normative neural adaptation function of the auditory pathway serves as guide for improving diagnostic utility of both ECochG and ABR using CLAD as a reliable technique in distinguishing inner ear and auditory nerve disorders.

Assessment of low-frequency hearing with narrow-band chirp-evoked 40-Hz sinusoidal auditory steady-state response.

Objective To determine the clinical utility of narrow-band chirp-evoked 40-Hz sinusoidal auditory steady state responses (s-ASSR) in the assessment of low-frequency hearing in noisy participants. Design Tone bursts and narrow-band chirps were used to respectively evoke auditory brainstem responses (tb-ABR) and 40-Hz s-ASSR thresholds with the Kalman-weighted filtering technique and were compared to behavioral thresholds at 500, 2000, and 4000 Hz. A repeated measure ANOVA and post-hoc t-tests, and simple regression analyses were performed for each of the three stimulus frequencies. Study sample Thirty young adults aged 18-25 with normal hearing participated in this study. Results When 4000 equivalent response averages were used, the range of mean s-ASSR thresholds from 500, 2000, and 4000 Hz were 17-22 dB lower (better) than when 2000 averages were used. The range of mean tb-ABR thresholds were lower by 11-15 dB for 2000 and 4000 Hz when twice as many equivalent response averages were used, while mean tb-ABR thresholds for 500 Hz were indistinguishable regardless of additional response averaging. Conclusion Narrow-band chirp-evoked 40-Hz s-ASSR requires a ∼15 dB smaller correction factor than tb-ABR for estimating low-frequency auditory threshold in noisy participants when adequate response averaging is used.

Tone-Burst Auditory Brainstem Response and Cortical Potentials in Diagnosis of Syndromic Auditory Neuropathy Spectrum Disorder.

In this study, we report our findings of comprehensive evaluation in a man with syndromic craniofacial features, cognitive impairment, and hearing loss. The patient underwent psychological and genetic testing and screening for 133 genetic mutations associated with hearing loss, as well as extensive audiological evaluation to assess the auditory pathway between the middle ear and the auditory cortex. Psychological testing showed moderate cognitive impairment. Genetic testing did not reveal a genetic mutation for hearing loss. Audiological evaluation revealed mixed hearing loss and signs of auditory neuropathy spectrum disorder (ANSD) despite absence of otoacoustic emissions and an absent click-evoked auditory brainstem response (ABR) without recording of cochlear microphonics (CM). ANSD was characterized by abnormal speech discrimination, bilateral robust CM to 2,000 Hz tone-burst (TB) ABR, and abnormal left thalamocortical and cortical pathways diagnosed based on auditory middle latency and cortical N1-P2 responses. These behavioral and electrophysiological findings suggest post-synaptic ANSD at the brainstem level. An abnormal left thalamocortical auditory pathway may be attributable to the combined effect of lack of neural synchrony secondary to ANSD mainly on the left and/or brain injury. The findings in this study support the use of TB ABR and auditory cortical potentials in the ANSD test protocol and in patients with craniofacial anomalies.

DPOAEs and contralateral acoustic stimulation and their link to sound hypersensitivity in children with autism.

OBJECTIVE: The hypersensitivity of children with autism to sound is a relatively unexplained behavior. The goal of the current study was to investigate the DPOAE characteristics of children with autism compared to a control group. DESIGN: DPOAEs with and without contralateral stimuli were measured in two groups in three different conditions. STUDY SAMPLE: The study employed 14 children with autism and a control group with 28 age-matched participants. RESULTS: In the without-contralateral stimulus condition, the overall S/N of DPOAEs was greater for the control group compared to the autism group (p < 0.0005). For both groups, the DPOAE S/N increased as a function of frequency in both ears. In the with contralateral stimulus condition, group and ear effects were noticed, however, no age, frequency, or contralateral stimulus type (BBN vs. 1000 Hz) effect could be detected. CONCLUSIONS: Presence of reduced DPOAEs in the autism group does not support the hypothesis that sound hypersensitivity in children with autism may be related to overactive outer hair cells function; rather it may be due to early cochlear dysfunction. Also, sound hypersensitivity in the autism group may be due to abnormality of the efferent auditory pathway as shown by lack of sufficient contralateral suppression.

Evaluation of patients with vertigo of vertebrobasilar insufficiency origin using auditory brainstem response, electronystagmography, and transcranial Doppler.

OBJECTIVES: Vertigo can be a manifestation of underlying vertebrobasilar stroke in older adults. The study objectives were to investigate the correlation, sensitivity, and specificity of the auditory brainstem response (ABR), electronystagmorgraphy (ENG), and transcranial Doppler (TCD) collectively to distinguish between vertigo due to vertebrobasilar insufficiency (VBI) and vertigo due to non-VBI. DESIGN: Prospective experimental study comparing ENG, ABR, and TCD battery findings between two groups of patients with vertigo and a control group. STUDY SAMPLE: Participants included 14 patients with vertigo of VBI origin, 14 patients with vertigo of non-VBI, and 11 matched controls. RESULTS: Participants with VBI had more abnormal findings in the ENG (86%), TCD (72%), and ABR (64%) compared to the non-VBI group (64%, 21%, and 7%, respectively) and the control group. The combined battery revealed positive correlations, 64% sensitivity, and 84% positive predictive value (PPV) in the VBI group, and 100% specificity with lack of correlations in the non-VBI group. CONCLUSIONS: The modest sensitivity and PPV helps with early detection of VBI, thus preventing risk of vertebrobasilar stroke in 84% to 64% of patients. The 100% specificity in the non-VBI group rules out VBI, thus reducing the referral rate for unnecessary, diagnostic evaluations and ineffective treatment.

Examining the Profile of Noise-Induced Cochlear Synaptopathy Using iPhone Health App Data and Cochlear and Brainstem Electrophysiological Responses to Fast Clicks Rates.

Little is known about objective classifying of noise exposure risk levels in personal listening device (PLD) users and electrophysiologic evidence of cochlear synaptopathy at very fast click rates. The aim of the study was to objectively classify noise exposure risk using iPhone Health app and identify signs of cochlear synaptopathy using behavioral and electrophysiologic measures. Thirty normal-hearing females (aged 18-26 years) were grouped based on their iPhone Health app's 6-month listening level and noise exposure data into low-risk and high-risk groups. They were assessed using a questionnaire, extended high-frequency (EHF) audiometry, QuickSIN test, distortion-product otoacoustic emission (DPOAE), and simultaneous recording of electrocochleography (ECochG) and auditory brainstem response (ABR) at three click rates (19.5/s, 97.7/s, 234.4/s). A series of ANOVAs and independent samples t -test were conducted for group comparison. Both groups had within-normal EHF hearing thresholds and DPOAEs. However, the high-risk participants were over twice as likely to suffer from tinnitus, had abnormally large summating potential to action potential amplitude and area ratios at fast rates, and had slightly smaller waves I and V amplitudes. The high-risk group demonstrated a profile of behavioral and objective signs of cochlear synaptopathy based on ECochG and ABR recordings at fast click rates. The findings in this study suggest that the iPhone Health app may be a useful tool for further investigation into cochlear synaptopathy in PLD users.

Comparing Simultaneous Electrocochleography and Auditory Brainstem Response Measurements Using Three Different Extratympanic Electrodes.

BACKGROUND: Various extratympanic recording electrodes have been used to make electrocochleography (ECochG) and auditory brainstem response (ABR) measurements in clinics, translational research, and basic science laboratories. However, differences may exist in ECochG and ABR measurements depending on the different types of extratympanic electrodes that are used. PURPOSE: The purpose of this research is to compare simultaneously recorded ECochG and ABR responses using three different extratympanic electrodes. This research helps clinicians and researchers to understand how electrode types and recording sites influence EcochG and ABR results. In addition, our findings could provide more normative data to the ECochG and ABR literature as well as give perspective on a preferred electrode approach when performing simultaneous ECochG and ABR testing. RESEARCH DESIGN: Ours was a repeated-measures study with measurements being made from individual participants on two separate sessions. STUDY SAMPLE: Twenty young adult females with normal hearing. PROCEDURE: A three-channel recording system was used to simultaneously record ECochG and ABR measurements in response to alternating polarity click stimuli. In each session, measurements were simultaneously recorded with a TipTrode electrode and one of the tympanic membrane (TM) electrodes. DATA COLLECTION AND ANALYSIS: Suprathreshold summating potential (SP) and action potential (AP) of the ECochG and waves I, III, and V of the ABR, and threshold responses (AP and wave V) were identified. RESULTS: Compared with the ear canal TipTrode electrode, TM electrodes yielded suprathreshold amplitudes that were larger than those from the ear canal electrode, smaller SP-AP ratios, lower AP thresholds, and less variability. These findings can help guide choices made by clinicians, translational investigators, and basic science researchers on which type of extra-tympanic electrode to use for their intended purpose.

Medial Olivocochlear Reflex Effect on Cochlear Response in Humans: Elicitor Side and Level.

BACKGROUND: Understanding the functional differences between crossed and uncrossed medial olivocochlear (MOC) neurons has been of interest to researchers for decades. Previous reports revealed conflicting results about which MOC pathway, crossed or uncrossed, is stronger in humans. Both crossed and uncrossed MOC neurons synapse at the base of the outer hair cells (OHCs) in each ear. OHCs generate the cochlear microphonic, which is a major contributor to the cochlear response (CR) PURPOSE: The current study investigated the effects of eliciting the crossed and uncrossed MOC reflex (MOCR) on CR in humans with three levels of noise. RESEARCH DESIGN: Normal-hearing, young adults (n = 16) participated in this study. The CR was recorded using 500 Hz tone-burst stimuli presented at 80 dB nHL. To examine the crossed and uncrossed MOCR, CR was recorded without and with continuous ipsilateral or contralateral broadband noise (BBN) at three levels (40, 50, and 60 dB SPL). DATA ANALYSIS: Analysis of the CR was completed using the amplitude of the response extracted using fast Fourier transform. Statistical analysis was completed using repeated measures analysis of variance and post-hoc analysis. RESULTS: Compared with baseline, the presentation of BBN, specifically contralaterally, resulted in CR enhancement with no significant difference as a function of the three BBN levels. Greater enhancement of the CR amplitude was observed with contralateral than ipsilateral BBN elicitor. CONCLUSIONS: The current findings suggest that a contralateral elicitor of the uncrossed MOC pathway results in a larger CR amplitude enhancement compared with an ipsilateral elicitor of the crossed MOC pathway, regardless of the elicitor level. Eliciting the MOCR appears to modulate the OHCs function. Furthermore, assessing the MOCR with the 500 Hz CR with BBN elicitors at moderate levels should separate its effects (i.e., increase response amplitude) from those associated with the middle ear muscle reflex (i.e., reduce response amplitude).

Human medial olivocochlear reflex: Contralateral activation effect on low and high frequency cochlear response.

The role of the medial olivocochlear (MOC) reflex has been investigated by assessing changes of cochlear responses (CR) in humans. The CR consists of pre-neural and neural potentials originating from the inner ear, and at high signal levels is dominated by cochlear microphonic (CM). The CM originates from the outer hair cells, where the MOC fibers synapse, and there is little research about using it to investigate the MOC reflex in humans. The current study aimed to investigate the effect of contralateral activation of the MOC reflex on the CR in humans. The CR was recorded in female adults (n = 16) to 500 and 2000 Hz tone burst stimuli presented at 80 dB nHL with and without contralateral broadband noise (CBBN) at 40 dB SPL. Two different methods were utilized to quantify and analyze the CR data: peak amplitude and power spectrum. Results revealed enhancement of the CR amplitude with activation of the MOC reflex. Furthermore, on average, enhancement in the CR amplitude was observed to 500 Hz, but not 2000 Hz stimulus. The CR power spectrum findings revealed similar findings to the peak amplitude. These findings indicate the MOC effect is measurable when using a low frequency stimulus, but not high frequency. Moreover, the CR could be used as a potential tool to study the MOC reflex in humans.

Air-conduction auditory steady-state response: comparison of interchannel recording using two modulation frequencies.

BACKGROUND: Two-channel auditory steady-state response (ASSR) recording at high and low MF (modulation frequency) most likely provides an insight about the response amplitude and latency from different directions at the brainstem level and at the thalamus or cortical level. Little is known about the combined relationship between MF (39 and 79 Hz) and electrode montages (ipsilateral and contralateral) to single AM (amplitude modulation) tones on the ASSR amplitude and latency. PURPOSE: To determine if ipsilateral versus contralateral response asymmetries are present at the brainstem level (79 Hz ASSR) and at the thalamus or cortical levels (39 Hz ASSR). RESEARCH DESIGN: Descriptive and inferential statistics for interchannel ipsilateral and contralateral ASSR amplitude and latency to 79 and 39 Hz. STUDY SAMPLE: Twenty-five normal-hearing, right-handed young female adults participated in the study. All participants were right-handed, and their age ranged between 18 to 28 years (mean 24.5 +/- 1.6 years). DATA COLLECTION AND ANALYSIS: Ipsilateral and contralateral ASSR to 39 and 79 Hz MF and 100% AM stimuli were recorded at 500, 2000, and 4000 Hz carrier frequencies at 65 dB SPL. The ASSR amplitudes and phases were determined for each MF across Fc (carrier frequency) for the two channels to the test (right) ear. ASSR amplitude and latency between recording montages for each MF and across carrier frequency were compared by computing two-way repeated measures ANOVA. RESULTS: The mean ipsilateral ASSR amplitudes to 39 Hz across frequency were slightly larger (228.6 +/- 61.6 microV) than the contralateral response amplitude (223.2 +/- 78 microV) while the mean ipsilateral 79 Hz amplitudes were smaller (127.3 +/- 114.8) compared to contralateral 79 Hz amplitude (154.6 +/- 112.7 microV). For latency response, the mean ipsilateral/contralateral latency difference, on average, was 1 msec or less for both MFs. Results, in normal female adults, indicated no significant interchannel ASSR asymmetries for amplitude and latency (p > 0.05) at the brainstem (79 Hz ASSR) and at the thalamus or cortical levels (39 Hz ASSR). CONCLUSIONS: Interchannel ipsilateral and contralateral ASSR amplitude and latency to 79 and 39 Hz are not significantly different in normal, young female adults. Two-channel recording of ASSR to different MFs may be of clinical value in otoneurologic assessment.

Human Summating Potential Using Continuous Loop Averaging Deconvolution: Response Amplitudes Vary with Tone Burst Repetition Rate and Duration.

Electrocochleography (ECochG) to high repetition rate tone bursts may have advantages over ECochG to clicks with standard slow rates. Tone burst stimuli presented at a high repetition rate may enhance summating potential (SP) measurements by reducing neural contributions resulting from neural adaptation to high stimulus repetition rates. To allow for the analysis of the complex ECochG responses to high rates, we deconvolved responses using the Continuous Loop Averaging Deconvolution (CLAD) technique. We examined the effect of high stimulus repetition rate and stimulus duration on SP amplitude measurements made with extratympanic ECochG to tone bursts in 20 adult females with normal hearing. We used 500 and 2,000 Hz tone bursts of various stimulus durations (12, 6, 3 ms) and repetition rates (five rates ranging from 7.1 to 234.38/s). A within-subject repeated measures (rate x duration) analysis of variance was conducted. We found that, for both 500 and 2,000 Hz stimuli, the mean deconvolved SP amplitudes were larger at faster repetition rates (58.59 and 97.66/s) compared to slower repetition rates (7.1 and 19.53/s), and larger at shorter stimulus duration compared longer stimulus duration. Our concluding hypothesis is that large SP amplitude to short duration stimuli may originate primarily from neural excitation, and large SP amplitudes to long duration, fast repetition rate stimuli may originate from hair cell responses. While the hair cell or neural origins of the SP to various stimulus parameters remains to be validated, our results nevertheless provide normative data as a step toward applying the CLAD technique to understanding diseased ears.

40-Hz Sinusoidal Auditory Steady-State Response and Tone Burst Auditory Brainstem Response Using a Kalman Filter to Determine Thresholds Pre- and Post-Myringotomy With Grommet Tube in Children With Mild, Low-Frequency Conductive Hearing Loss.

PURPOSE: Accurate estimation of mild, low-frequency hearing loss is difficult in young children. This study aimed to determine the accuracy of 40-Hz sinusoidal auditory steady-state response (sASSR) compared with tone burst auditory brainstem response (TB-ABR) to detect mild, low-frequency hearing loss in children with otitis media with effusion and to measure postoperative thresholds. METHODS: Thresholds at 500 and 4000 Hz were measured behaviorally and electrophysiologically using TB-ABR and 40-Hz sASSR with a Kalman filter in 26 children with otitis media with effusion. Recording was conducted preoperatively and postoperatively while children were actively awake. Repeated measures mixed analyses of variance were conducted to determine effects among measures and the two test frequencies. RESULTS: Both 40-Hz sASSR and TB-ABR accurately detected preoperative and postoperative thresholds and were within 5-10 dB of the behavioral thresholds at 4000 Hz. At 500 Hz, the mean 40-Hz sASSR threshold was only 5 dB above the behavioral thresholds and 18 dB better than the 500-Hz ABR threshold. Positive correlations were found but not between 40-sASSR and TB-ABR at 500 Hz. Also, the interrater judgment of the response was better for sASSR (89%) than TB-ABR (83%). CONCLUSION: The 40-Hz sASSR is more accurate than TB-ABR in determining a mild, low-frequency threshold.

Distortion-product otoacoustic emissions and contralateral suppression findings in children with Asperger's Syndrome.

OBJECTIVES: Children with Asperger's Syndrome (AS) often demonstrate auditory behaviors such as hypersensitivity to sounds and poor performance in noisy environments. These auditory behaviors may be related to cochlear dysfunction and abnormal medial olivocochlear bundle (MOCB) activity. The objective of this study was to examine the distortion-product otoacoustic emissions (DPOAEs) with and without contralateral white noise to evaluate outer hair cell activity and MOCB activity in children with AS. METHODS: A case control study where 18 boys with AS and 18 age-matched control subjects participated in the study. For both groups, DPOAEs were recorded at 4031, 2627, 1969, and 1359 Hz f2 frequencies with and without contralateral white noise at 30 dB SL. DPOAE SNRs and difference scores were analyzed for possible differences between both groups and age subgroups (young and old children). RESULTS: In the quiet condition, there were no significant group or ear differences in DPOAEs SNR. However, DPOAEs SNR were larger at 4031 Hz than at lower frequencies in both groups, mostly due to negative effect of background noise on low frequency response. Contralateral noise resulted in both suppression and enhancement of the DPOAE SNRs in 93% of the control group and 90% of the AS group. However, there were no significant differences in suppression and enhancement between the two groups or age subgroups. The young controls had right ear advantage and significantly larger suppression at all frequencies except 4031 Hz than old controls. The young children with AS had slight left ear advantage and significantly larger suppression only at 2672 Hz compared to the old children with AS. CONCLUSIONS: The results, indicating minor differences in DPOAEs and contralateral suppression and enhancement of DPOAEs between both control and AS groups and age subgroups, suggest subtle differences in the function of the outer hair cells and the MOCB activity. Therefore, other central auditory processing in the temporal lobe, limbic system and autonomic nervous system may be involved in the generation of hypersensitivity to sounds and difficulty understanding in noisy environments in children with AS.

Optimizing otoscopy competency in audiology students through supplementary otoscopy training.

BACKGROUND: Scope of practice in audiology encompasses proficiency in visual inspection of ear canal and tympanic membrane (TM) as well as otoscopy interpretation skills to determine normal versus abnormal conditions of outer and middle ear. Audiology students can develop skills in otoscopy through education and supervised training. Studies have shown that additional otoscopy training increased skills in medical students and general practitioners. However, educational and supervised practices targeting otoscopy competency during audiology graduate coursework are lacking. Also, no studies have attempted to determine otoscopy skills among audiology students. PURPOSE: To determine the effectiveness of the otoscopy training model on clinical competency and confidence level of audiology students in performing and interpreting otoscopy. RESEARCH DESIGN: A combination of experimental treatment design with random assignment of treatment and control groups and delayed treatment for control group. STUDY SAMPLE: Thirty-two first- and second-year audiology graduate students who were enrolled in a pediatric audiology class participated in this study. Students were randomly assigned to the control (n = 16, 14 females) or experimental (n = 16, 14 females) group. INTERVENTION: Participants in the experimental group received supplementary otoscopy training including didactic otoscopy lectures as well as clinical training using manikin ears. The control group received the same pretest and posttest and then completed a third assessment (posttest 2) after receiving the same training. DATA COLLECTION AND ANALYSIS: An evaluation of knowledge and skills regarding otoscopy between groups and time was conducted at three times: (a) pretraining, (b) upon completion of training for the experimental group, (c) upon completion of training by the control group. The evaluation consisted of a written exam, a clinical exam, and a self-perception rating of confidence. Both written exam scores and clinical exam scores (otoscopy manikin) were analyzed via two-way analyses of variance (ANOVAs), whereas chi-square (χ²) statistic was conducted to evaluate the effects of training on the confidence level of students of both groups. RESULTS: Experimental and control groups demonstrated significant increased overall competency in otoscopy following the otoscopy training model with didactic and laboratory components. Posttest confidence ratings showed increases in all groups, and there were no significant differences between groups. CONCLUSIONS: The need for supplementary otoscopy training was warranted by low knowledge and clinical competency in otoscopy skills of audiology students as measured by pretest mean scores. After completing the training, both experimental and control groups showed significant improvement in knowledge and competency. Results also suggest that perceived confidence ratings may be misleading in determining students' clinical otoscopy skills.

Wideband energy reflectance findings in presence of normal tympanogram in children with Down's syndrome.

OBJECTIVES: The prevalence of middle ear disorders in children with Down syndrome is higher than normal children due to the associated craniofacial abnormalities. The goal of this study is to evaluate middle ear function using wideband energy reflectance at ambient pressure in 14 young children with Down syndrome and matched control group (2½-5 years old; N=19 ears per group) who each have a normal 226Hz tympanogram. METHODS: All children underwent otoscopic examination, hearing screening using play audiometry (500-4000Hz), and middle ear testing using 226Hz tympanometry and wideband energy reflectance. The chirp signals for the wideband energy reflectance were presented to the child's ear at 65dB SPL stimulus level and the recording was done over 220-8000Hz range. The measured energy reflectance represents the ratio of the sound energy reflected from the tympanic membrane to the incident sound energy transmitted to the middle ear at a specific frequency. Paired Samples t-test was computed for the mean, 95th, 75th, 25th, and 5th percentile data of each frequency of the two groups. RESULTS: Despite the presence of normal tympanometric findings in both groups, results revealed abnormal wideband energy reflectance findings in 63% of the children with Down syndrome compared to the normal wideband energy reflectance findings in the control group. The mean energy reflectance ratio of the Down syndrome group was abnormally lower than that of the control at 5700-8000Hz (p<0.0005). The 5th and 95th percentile ratios of the Down syndrome group fell outside the 5th and 95th percentile of the control group (p<0.0005). CONCLUSIONS: Abnormally low energy reflectance ratios above 4000Hz in the presence of normal tympanograms in the Down syndrome group may suggest associated congenital middle ear anomalies in children with DS. The present findings suggest that wideband energy reflectance has the potential to be of more practical value in children with DS than tympanometry. Further research with a larger number of Down syndrome children will illuminate the potential of wideband energy reflectance in diagnosing middle ear disorders in children with Down syndrome.

The promise of service learning in a pediatric audiology course on clinical training with the pediatric population.

PURPOSE: This study investigated the effectiveness of service learning (SL) and its impact on students' clinical competency, interest in pediatric audiology as a career, and levels of community engagement, as well as its impact on the community. METHOD: Forty-eight students enrolled in an SL pediatric audiology course providing hearing and middle ear testing to 292 children, ages 6 months to 5 years. Another 10 non-SL students served as a control group. SL surveys were administered to students before and after the SL experience and post hoc to the non-SL group to assess their perceived readiness for evaluating children and their interest in pediatric audiology. Parents and community partner staff members completed another survey to provide feedback about their experience with the SL activity. RESULTS: The students' ratings were higher post-SL than pre-SL, and their learning gain was positively ranked post-SL compared with the non-SL group. Also, 71% of the SL students expressed positive interest in pediatric audiology post-SL compared with 37% of the non-SL group. Responses from community partners were also positive. CONCLUSIONS: Embedding SL into a pediatric audiology course increased student interest in pediatric audiology as a career and enhanced readiness to evaluate young children.

Effect of interdisciplinary service learning experience for audiology and speech-language pathology students working with adults with dementia.

PURPOSE: An interdisciplinary service learning (SL) experience with audiology and speech-language pathology students was designed to examine changes in students' attitudes toward adults with dementia following an SL experience in which they socialized with nursing home residents who had dementia. METHOD: Nineteen audiology and 24 speech-language pathology students completed an SL course, and 14 audiology and 18 speech-language pathology students did not participate in the SL course. The students interacted with 24 nursing home residents with dementia; specifically, the audiology students conducted 2 hearing evaluations with the residents, and the speech-language pathology students socialized with the residents during 15 visits. The students' attitudes toward older adults with dementia were assessed using Kogan's Attitudes Toward Old People Scale (Kogan, 1961) and qualitative analysis of their journal entries. The results were compared across groups over time. RESULTS: The SL groups showed more positive attitudes than the non-SL students, and their later journal entries were more positive than earlier entries. CONCLUSIONS: This SL experience provided clinical opportunities for audiology and speech-language pathology students to work with adults with dementia. Direct contact with the residents resulted in more positive attitudes toward older adults in residential facilities.

Reliability of electric response audiometry using 80 Hz auditory steady-state responses.

The reliability of the Auditory Steady State Response (ASSR) has not been thoroughly evaluated despite its recent application as a clinical tool for threshold estimation. The purpose of this study was to examine test-retest (TR) reliability of ASSR threshold estimates in an empirical research design. The ASSR, tested using modulation frequencies approximately 80 Hz and above, was evaluated against pure tone audiometry (PTA), and the slow vertex potential (SVP, N1-P2). Sixteen normal-hearing young female adults were tested twice, one week apart. Varying degrees of sensorineural hearing loss of a notched configuration were simulated with filtered masking noise. Test-retest reliability was assessed using Pearson-product moment correlation analysis, supplemented by other post-hoc analyses. Results demonstrated moderately strong TR reliability for ASSR at 1000, 2000 and 4000 Hz (r = 0.83-0.93); however, the reliability of ASSR at 500 Hz was weaker (r = 0.75). Results suggest that ASSR-ERA is a reliable test at mid-high frequencies, at least with the configuration and degrees of simulated sensorineural hearing loss examined in this study.

Validity and accuracy of electric response audiometry using the auditory steady-state response: evaluation in an empirical design.

The validity and accuracy of the application of the auditory steady-state response (ASSR) to electric response audiometry (ERA) was tested further in a study permitting subjects to be their own controls for hearing loss. Simulated sensorineural hearing loss (SSHL) of complex configuration and varying degrees was effected using filtered masking noise. Thresholds estimated via ASSR-ERA were compared to those measured via conventional pure-tone audiometry. Further, the slow vertex potential N1-P2 was recorded to permit a comparison with an evoked-response test of common content validity and known accuracy. Results in a homogeneous subject sample demonstrated strong interest correlation and agreement within 10 dB at 1000 to 4000 Hz (on average), but not at 500 Hz. The configurations determined by ASSR-ERA followed behavioral audiometric patterns well, except for the mildest degree of SSHL tested. Consequently, limitations of ERA remain, although ASSR-ERA appears to be quite valid overall and promises (justifiably) broad clinical applicability.