Comment on Yathiraj & Vanaja (2018), "Criteria to Classify Children as Having Auditory Processing Disorders".

Purpose The purpose of this letter is to comment on an article by Yathiraj and Vanaja (2018) titled "Criteria to Classify Children as Having Auditory Processing Disorders." Conclusions Although there is a need to diagnose auditory processing disorders in school-age children, the criteria recommended by Yathiraj and Vanaja (2018) are not empirically derived. Continued research is needed to clearly define an auditory processing disorder in this population and develop highly sensitive and specific tests to diagnose the disorder.

The Effect of Kalman-Weighted Averaging and Artifact Rejection on Residual Noise During Auditory Brainstem Response Testing.

Purpose Low residual noise (RN) levels are critically important when obtaining electrophysiological recordings of threshold auditory brainstem responses. In this study, we examine the effectiveness and efficiency of Kalman-weighted averaging (KWA) implemented on the Vivosonic Integrity System and artifact rejection (AR) implemented on the Intelligent Hearing Systems SmartEP system for obtaining low RN levels. Method Sixteen adults participated. Electrophysiological measures were obtained using simultaneous recordings by the Vivosonic and Intelligent Hearing Systems for subjects in 2 relaxed conditions and 4 active motor conditions. Three averaging times were used for the relaxed states (1, 1.5, and 3 min) and for the active states (1.5, 3, and 6 min). Repeated-measures analyses of variance were used to examine RN levels as a function of noise reduction strategy (i.e., KWA, AR) and averaging time. Results Lower RN levels were obtained using KWA than AR in both the relaxed and active motor states. Thus, KWA was more effective than was AR under the conditions examined in this study. Using KWA, approximately 3 min of averaging was needed in the relaxed condition to obtain an average RN level of 0.025 µV. In contrast, in the active motor conditions, approximately 6 min of averaging was required using KWA. Mean RN levels of 0.025 µV were not attained using AR. Conclusions When patients are not physiologically quiet, low RN levels are more likely to be obtained and more efficiently obtained using KWA than AR. However, even when using KWA, in active motor states, 6 min of averaging or more may be required to obtain threshold responses. Averaging time needed and whether a low RN level can be attained will depend on the level of motor activity exhibited by the patient.

Author Response to Peck (2018), "Questionable Use of 'Nonorganic' in 'Estimating Nonorganic Hearing Thresholds'".

PURPOSE: The purpose of this letter is to respond to Dr. Peck's (2018) letter to the editor regarding the use of the term "nonorganic" to describe hearing loss, demonstrated by the pure tone audiogram that cannot be explained or is greater than what can be explained by a physiological auditory disorder. CONCLUSIONS: We prefer the term "nonorganic" rather than the term "false and exaggerated hearing loss." "Nonorganic," in our view, is a nonjudgmental term and, as stated by Austen and Lynch (2004), implies "as little as possible about its cause" (p. 450).

Clinicians' Guide to Obtaining a Valid Auditory Brainstem Response to Determine Hearing Status: Signal, Noise, and Cross-Checks.

PURPOSE: The auditory brainstem response (ABR) is a powerful tool for making clinical decisions about the presence, degree, and type of hearing loss in individuals in whom behavioral hearing thresholds cannot be obtained or are not reliable. Although the test is objective, interpretation of the results is subjective. METHOD: This review provides information about evidence-based criteria, suggested by the 2013 Newborn Hearing Screening Program guidelines, and the use of cross-check methods for making valid interpretations about hearing status from ABR recordings. RESULTS: The use of an appropriate display scale setting, templates of expected response properties, and objective criteria to estimate the residual noise, signal level, and signal-to-noise ratio will provide quality data for determining ABR thresholds. Cross-checks (e.g., immittance measures, otoacoustic emissions testing, functional indications of a child's hearing) are also needed to accurately interpret the ABR. CONCLUSIONS: Using evidence-based ABR signal detection criteria and considering the results within the context of other physiologic tests and assessments of hearing function will improve the clinician's accuracy for detecting hearing loss and, when present, the degree of hearing loss. Diagnostic accuracy will ensure that appropriate remediation is initiated and that children or infants with normal hearing are not subjected to unnecessary intervention.

Unraveling the Mystery of Auditory Brainstem Response Corrections: The Need for Universal Standards.

BACKGROUND: The auditory brainstem response (ABR) is used to estimate behavioral hearing thresholds in infants and difficult-to-test populations. Differences between the toneburst ABR and behavioral thresholds exist making the correspondence between the two measures less than perfect. Some authors have suggested that corrections be applied to ABR thresholds to account for these differences. However, because there is no agreed upon universal standard, confusion regarding the use of corrections exists. PURPOSE: The primary purpose of this article is to review the reasoning behind and use of corrections when the toneburst ABR is employed to estimate behavioral hearing thresholds. We also discuss other considerations that all audiologists should be aware of when obtaining and reporting ABR test results. RESULTS: A review of the purpose and use of corrections reveals no consensus as to whether they should be applied or which should be used. Additionally, when ABR results are adjusted, there is no agreement as to whether additional corrections for hearing loss or the age of the client are necessary. This lack of consensus can be confusing for all individuals working with hearing-impaired children and their families. CONCLUSIONS: Toneburst ABR thresholds do not perfectly align with behavioral hearing thresholds. Universal protocols for the use of corrections are needed. Additionally, evidence-based procedures must be employed to obtain valid ABRs that will accurately estimate hearing thresholds.

Estimating Nonorganic Hearing Thresholds Using Binaural Auditory Stimuli.

PURPOSE: Minimum contralateral interference levels (MCILs) are used to estimate true hearing thresholds in individuals with unilateral nonorganic hearing loss. In this study, we determined MCILs and examined the correspondence of MCILs to true hearing thresholds to quantify the accuracy of this procedure. METHOD: Sixteen adults with normal hearing participated. Subjects were asked to feign a unilateral hearing loss at 1.0, 2.0, and 4.0 kHz. MCILs were determined. Subjects also made lateralization judgments for simultaneously presented tones with varying interaural intensity differences. RESULTS: The 90% confidence intervals, calculated for the distributions, indicate that the MCIL in 90% of cases would be expected to be very close to threshold to approximately 17-19 dB poorer than the true hearing threshold. How close the MCIL is to true threshold appears to be based on the individual's response criterion. CONCLUSIONS: Response bias influences the MCIL and how close an MCIL is to true hearing threshold. The clinician can never know a client's response bias and therefore should use a 90% confidence interval to predict the range for the expected true threshold. On the basis of this approach, a clinician may assume that true threshold is at or as much as 19 dB better than MCIL.

The Effects of FM and Hearing Aid Microphone Settings, FM Gain, and Ambient Noise Levels on SNR at the Tympanic Membrane.

BACKGROUND: Speech understanding in noise is challenging for individuals with hearing loss. Hearing aids (HAs) alone are typically unable to resolve these listening difficulties. Frequency modulation (FM) systems or other remote microphone accessories, coupled to HA, are intended to provide listeners with a good signal-to-noise ratio (SNR), thus improving signal audibility and speech understanding. PURPOSE: The goal of this study was to assess variables that influence SNR at the tympanic membrane (TM) when using a remote microphone/HA combination. We examined microphone setting, transmission system gain, and background noise levels using (1) mathematical computations to manipulate variables and observe the outcomes and (2) behavioral testing. RESEARCH DESIGN: This study used mathematical computations to estimate SNR at the TM and a mixed-model experimental design to confirm a subset of the calculations. STUDY SAMPLE: Ten children with normal hearing (mean age, 13.7 yr) and ten adults with high-frequency sensorineural hearing loss (mean age, 49.6 yr) participated. DATA COLLECTION AND ANALYSIS: Speech recognition thresholds were obtained using Bamford-Kowal-Bench sentences in the presence of noise. Participants used an FM system coupled to an HA in an FM-only and an FM + HA microphone condition. RESULTS: Better performance was observed in the FM-only compared to FM + HA condition with the overall amount of the FM-only advantage slightly larger than the mathematical calculations predicted. Further calculations demonstrated that (1) when using an FM-only microphone setting, the SNR at the TM is determined primarily by the SNR at the FM microphone; (2) when both HA and FM microphones are active, the SNR is determined by the highest level of the speech, which is typically at the FM microphone, and the highest level of noise at either the FM or HA microphone; (3) increasing FM gain has no impact on SNR in an FM-only condition; and (4) in an FM + HA condition, increasing FM gain improves SNR. The amount of improvement depends on noise levels at the FM and HA microphones. When the noise levels are similar at the two microphones, an improvement in SNR of ∼2 dB is expected. Greater improvement is expected when the level of the noise at the FM microphone can be reduced relative to the level at the HA microphone. CONCLUSIONS: When using a remote microphone system coupled with a listener's HA, several variables influence SNR at the TM. Two variables that can be manipulated by programming of either or both devices are the microphone setting and gain setting. Mathematical calculations were used to determine the specific influence of and interactions between these variables and showed the importance of (1) managing noise levels to optimize SNR; and (2) counseling clients regarding optimal use of and realistic expectations from their system. This information is useful in the clinical management of persons with hearing loss, especially with the advent and affordability of wireless microphone accessories to assist listeners in background noise.

Audiometric Thresholds: Stimulus Considerations in Sound Field and Under Earphones.

PURPOSE: This study evaluates a new stimulus, FREquency Specific Hearing assessment (FRESH) noise, to obtain hearing thresholds and reviews the potential pitfalls of using narrow band noise. METHOD: Twelve adults with simulated gradually sloping hearing loss and 12 adults with steeply sloping hearing loss participated. Hearing thresholds were measured in sound field and under a supraaural earphone for FRESH noise, warbled tones, and narrowband noise. Pure-tone thresholds were also measured under the supraaural earphone. RESULTS: FRESH noise thresholds were similar to pure-tone and warbled-tone thresholds regardless of audiometric configuration. For the group with gradually sloping hearing loss, thresholds obtained with narrowband noise were approximately 4 dB better than those obtained with the other test stimuli. For the group with steeply sloping hearing loss, narrowband noise significantly underestimated hearing thresholds-the steeper the hearing loss, the greater the underestimation. CONCLUSIONS: When hearing loss is suspected, FRESH noise is appropriate for accurately determining audiometric thresholds in sound field and under earphones. A wider band, attention-getting stimulus such as narrowband noise can result in thresholds that are inaccurate. Clinical decision making regarding choice of test stimulus is discussed.

Hearing Thresholds, Minimum Response Levels, and Cross-Check Measures in Pediatric Audiology.

PURPOSE: Pediatric audiologists must identify hearing loss in a timely manner so that early intervention can be provided. In this article, the methods important for differentiating between a hearing threshold and minimum response level (MRL), important for an accurate diagnosis, are described. METHOD: Operant conditioning procedures, used during visual reinforcement audiometry and conditioned play audiometry, are reviewed. Case examples are provided that demonstrate the importance of using evidence-based procedures, evaluating the success of such procedures, and using cross-check measures for interpreting responses as thresholds or MRLs. RESULTS: Behavioral-hearing thresholds can be obtained when operant conditioning procedures are successful and cross-check measures corroborate the audiometric results. When MRLs are obtained, cross-check measures are critical in determining the likelihood of hearing loss and making follow-up recommendations. CONCLUSIONS: Early diagnosis of hearing loss is important so that intervention can be initiated within critical periods during infant and childhood learning. Accurate diagnosis depends on the audiologist, who must adhere to evidence-based procedures, use cross-check measures, and evaluate the validity of each procedure. Future research and guidelines are needed to examine decision-making processes in pediatric audiology that ensure diagnostic accuracy and timely intervention for infants and children identified with hearing loss.

Modeling the Influence of Acoustic Coupling of Hearing Aids on FM Signal-to-Noise Ratio.

PURPOSE: A model was developed to examine variables that influence signal-to-noise ratio (SNR) at the tympanic membrane (TM) when using a hearing aid (HA) and frequency modulated (FM) system. The model was used to explore how HA coupling influences SNR. METHOD: To generate the model, HA output was measured in a coupler. Known coupler to real-ear transformations and known values for vent (gain) loss as a function of coupling were also used. The model was verified by measuring sound pressure level (SPL) at the TM in 6 ears. RESULTS: The model predicts similar overall SNRs at the TM regardless of coupling method when HA and FM microphones are active. The primary difference in SNR is in the low frequencies and depends on the amount of low frequency insertion gain and the noise levels at the HA and FM microphones. CONCLUSIONS: A model was developed to explore how complex variables contribute to SNR at the TM. One variable, HA coupling, is predicted to have only a minimal effect on SNR at the TM when there is HA gain. Further studies will be needed to assess the real-world effectiveness of an FM system coupled to an open- versus closed-fit HA.

Measuring the Advantage of Kalman-Weighted Averaging for Auditory Brainstem Response Hearing Evaluation in Infants.

PURPOSE: The purposes of this study were to (a) measure the effects of Kalman-weighted averaging methods on auditory brainstem response (ABR) threshold, latency, and amplitude; (b) translate lab findings to the clinical setting; and (c) estimate cost savings when ABRs can be obtained in nonsedated infants. METHOD: ABRs were recorded in 40 adults with normal hearing during induced motor noise conditions using the Kalman-weighted averaging method implemented on a commercial system, the Vivosonic Integrity (Vivosonic Inc., Toronto, Ontario, Canada). The device was then used to test 34 infants in awake and asleep states. The advantages of the Kalman-weighted averaging method were modeled in terms of time saved for conducting an ABR evaluation. RESULTS: Kalman-weighted ABR threshold estimates were 6-7 dB lower than with conventional methods during induced motor noise. When used to obtain ABRs in infants who were awake, the number of sweeps required to obtain a result was significantly greater than that required for a sleeping infant but well within the range for clinical application. CONCLUSIONS: The use of Kalman-weighted averaging provides a measurable advantage over conventional methods and may reduce costs for the pediatric audiology practice.

Auditory neuropathy spectrum disorder: a review.

PURPOSE: Auditory neuropathy spectrum disorder, or ANSD, can be a confusing diagnosis to physicians, clinicians, those diagnosed, and parents of children diagnosed with the condition. The purpose of this review is to provide the reader with an understanding of the disorder, the limitations in current tools to determine site(s) of lesion, and management techniques. METHOD: This article is a review of what is known about ANSD. It includes descriptions of assessment tools, causes of ANSD, and patient management techniques. CONCLUSIONS: This review is a guide to audiologists, speech-language pathologists, and early interventionists who work with individuals diagnosed with ANSD and/or their families. It highlights the need for more precise tools to describe the disorder in order to facilitate decisions about interventions and lead to better predictions of outcome.

Interaural multiple frequency tympanometry measures: clinical utility for unilateral conductive hearing loss.

BACKGROUND: Tympanometry is a routine clinical measurement of the acoustic immittance of the ear as a function of ear canal air pressure. The 226 Hz tympanogram can provide clinical evidence for conditions such as a tympanic membrane perforation, Eustachian tube dysfunction, middle ear fluid, and ossicular discontinuity. Multiple frequency tympanometry using a range of probe tone frequencies from low to high has been shown to be more sensitive than a single probe tone tympanogram in distinguishing between mass- and stiffness-related middle ear pathologies (Colletti, 1975; Funasaka et al, 1984; Van Camp et al, 1986). PURPOSE: In this study we obtained normative measures of middle ear resonance by using multiple probe tone frequency tympanometry. Ninety percent ranges for middle ear resonance and for interaural differences were calculated. RESEARCH DESIGN: In a mixed design, normative data were collected from both ears of male and female adults. STUDY SAMPLE: Twelve male and 12 female adults with normal hearing and normal middle ear function participated in the study. DATA COLLECTION AND ANALYSIS: Multiple frequency tympanograms were recorded with a commercially available immittance instrument (GSI Tympstar) to obtain estimates of middle ear resonant frequency (RF) using ΔB, positive tail, and negative tail methods. Data were analyzed using three-way mixed analyses of variance with gender as a between-subject variable and ear and method as within-subject variables. T-tests were performed, using the Bonferroni adjustment, to determine significant differences between means. RESULTS: Using the positive and negative tail methods, a wide range of approximately 500 Hz was found for middle ear resonance in adults with normal hearing and normal middle ear function. The difference in RF between an individual's ears is small with 90% ranges of approximately ±200 Hz, indicating that the right ear RF should be either 200 Hz higher or lower in frequency compared to the left ear. This was true for both negative and positive tail methods. CONCLUSION: Ninety percent ranges were calculated to determine the difference in middle ear resonance expected between an individual's ears. These ranges can provide critical normative values for determining how pathology in an ear with a unilateral conductive hearing loss is altering the mass or stiffness characteristics of the middle ear system.

The auditory brainstem response: latencies obtained in children while under general anesthesia.

BACKGROUND: The auditory brainstem response (ABR) test is frequently employed to estimate hearing sensitivity and assess the integrity of the ascending auditory system. In persons who cannot participate in conventional tests of hearing, a short-acting general anesthetic is used, recordings are obtained, and the results are compared with normative data. However, several factors (e.g., anesthesia, temperature changes) can contribute to delayed absolute and interpeak latencies, making it difficult to evaluate the integrity of the person's auditory brainstem function. PURPOSE: In this study, we investigated the latencies of ABR responses in children who received general anesthesia. RESEARCH DESIGN: Between subject. STUDY SAMPLE: Twelve children between the ages of 29 and 52 mo, most of whom exhibited a developmental delay but normal peripheral auditory function, comprised the anesthesia group. Twelve participants between the ages of 13 and 26 yr with normal hearing thresholds comprised the control group. DATA COLLECTION AND ANALYSIS: ABRs from a single ear from children, recorded under general anesthesia, were retrospectively analyzed and compared to those obtained from a control group with no anesthesia. ABRs were generated using 80 dB nHL rarefaction click stimuli. T-tests, corrected for alpha slippage, were employed to examine latency differences between groups. RESULTS: There were significant delays in latencies for children evaluated under general anesthesia compared to the control group. Delays were observed for wave V and the interpeak intervals I-III, III-V, and I-V. CONCLUSIONS: Our data suggest that caution is needed in interpreting neural function from ABR data recorded while a child is under general anesthesia.

Auditory-visual integration for speech by children with and without specific language impairment.

PURPOSE: It has long been known that children with specific language impairment (SLI) can demonstrate difficulty with auditory speech perception. However, speech perception can also involve the integration of both auditory and visual articulatory information. METHOD: Fifty-six preschool children, half with and half without SLI, were studied in order to examine auditory-visual integration. Children watched and listened to video clips of a woman speaking [bi] and [gi]. They also listened to audio clips of [bi], [di], and [gi], produced by the same woman. The effect of visual input on speech perception was tested by presenting an auditory [bi] combined with a visually articulated [gi], which tends to alter the phoneme percept (the McGurk effect). RESULTS: Both groups of children performed at ceiling when asked to identify speech tokens in auditory-only and congruent auditory-visual modalities. In the incongruent auditory-visual condition, a stronger McGurk effect was found for the normal language group compared with the children with SLI. CONCLUSION: Responses by the children with SLI indicated less impact of visual processing on speech perception than was seen with their normal peers. These results demonstrate that the difficulties with speech perception by SLI children extend beyond the auditory-only modality to include auditory-visual processing as well.

Auditory-visual speech integration by adults with and without language-learning disabilities.

UNLABELLED: Auditory and auditory-visual (AV) speech perception skills were examined in adults with and without language-learning disabilities (LLD). The AV stimuli consisted of congruent consonant-vowel syllables (auditory and visual syllables matched in terms of syllable being produced) and incongruent McGurk syllables (auditory syllable differed from visual syllable). Although the identification of the auditory and congruent AV syllables was comparable for the two groups, the reaction times to identify all syllables were longer in the LLD compared to the control group. This finding is consistent with previous research demonstrating slower processing in learning disabled individuals. Adults with LLD also provided significantly fewer integration-type or McGurk responses compared with their normal peers when presented with speech tokens representing a mismatch between the auditory and visual signal. These results suggest the poor integration for auditory-visual speech previously documented in children with poor language skills also occurs in adults with LLD. LEARNING OUTCOMES: The reader will be able to (1) describe the McGurk effect; (2) describe group differences (language learning disabled and control adults) in auditory and auditory-visual speech perception of consonant-vowel syllables.