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Hearing loss affects 31 million Americans, particularly veterans who were exposed to harmful levels of noise during military functions. Many veterans also receive treatment with ototoxic medications, which may exacerbate preexisting hearing loss. Thus, hearing loss is the most common and tinnitus the third most common service-connected disability among veterans. Poor implementation of hearing protection programs and a lack of audiometric testing during medical treatment leave veterans vulnerable to unrecognized and untreated hearing loss until speech communication is impaired. Individualized audiometric testing techniques, including assessment of high frequencies, can be used in clinical and occupational settings to detect early hearing loss. Antioxidants also may alleviate cochlear damage caused by noise and ototoxicity. Ultimately, hearing loss prevention requires education on reducing occupational and recreational noise exposure and counseling on the risks and options available to patients. Technological advances will improve monitoring, allow better noise engineering controls, and lead to more effective hearing protection. [ABSTRACT FROM AUTHOR]

A primary focus of research at the National Center for Rehabilitative Auditory Research (NCRAR) has been to develop methodology for rapid and efficient early detection of ototoxicity. It has been shown that an individualized, limited frequency range can be identified, which is sensitive to early ototoxic changes in the auditory system. In this study, a rapid identification protocol for identifying the uppermost target frequency within this sensitive range of ototoxicity (SRO) was investigated. In 36 of 42 ears, the target frequency found with the rapid identification protocol was the same as that found with the full-frequency baseline testing. Where differences occurred, target frequencies obtained by the two methods did not differ by more than one-half octave. This rapid identification protocol results in considerable time savings in ototoxicity monitoring, which will result in the capability to include more patients in a monitoring program. [ABSTRACT FROM AUTHOR]

BACKGROUND: There is disagreement about ototoxicity monitoring methods. Controversy exists about what audiometric threshold shift criteria should be used, which frequencies should be tested, and with what step size. An evaluation of the test performance achieved using various criteria and methods for ototoxicity monitoring may help resolve these issues. PURPOSE: (1) Evaluate test performance achieved using various significant threshold shift (STS) definitions for ototoxicity monitoring in a predominately veteran population; and (2) determine whether testing in (1/6)- or (1/3)-octave steps improves test performance compared to (1/2)-octave steps. RESEARCH DESIGN: A prospective, observational study design was used in which STSs were evaluated at frequencies within an octave of each subject's high-frequency hearing limit at two time points, an early monitoring test and the final monitoring test. STUDY SAMPLE: Data were analyzed from 78 ears of 41 patients receiving cisplatin and from 53 ears of 28 hospitalized patients receiving nonototoxic antibiotics. Cisplatin-treated subjects received a cumulative dosage > or =350 mg by the final monitoring test. Testing schedule, age, and pre-exposure hearing characteristics were similar between the subject groups. DATA COLLECTION AND ANALYSIS: Threshold shifts relative to baseline were examined to determine whether they met criteria based on magnitudes of positive STS (shifts of > or =5, 10, 15, or 20 dB) and numbers of frequencies affected (shifts at > or =1, 2, or 3 adjacent frequencies) for data collected using approximately (1/6)-, (1/3)-, or (1/2)-octave steps. Thresholds were confirmed during monitoring sessions in which shifts were identified. Test performance was evaluated with receiver operating characteristic (ROC) curves developed using a surrogate 'gold standard'; true positive (TP) rates were derived from the cisplatin-exposed group and false positive (FP) rates from the nonexposed, control group. Best STS definitions were identified that achieved the greatest areas under ROC curves or resulted in the highest TP rates for a fixed FP rate near 5%, chosen to minimize the number of patients incorrectly diagnosed with ototoxic hearing loss. RESULTS: At the early monitoring test, average threshold shifts differed only slightly across groups. Test-frequency step size did not affect performance, and changes at one or more frequencies yielded the best test performance. At the final monitoring test, average threshold shifts were +10.5 dB for the cisplatin group, compared with -0.2 dB for the control group. Compared with the (1/2)-octave step size used clinically, use of smaller frequency steps improved test performance for threshold shifts at > or =2 or > or =3 adjacent frequencies. Best overall test performance was achieved using a criterion cutoff of > or =10 dB threshold shift at > or =2 adjacent frequencies tested in (1/6)-octave steps. Best test performance for the (1/2)-octave step size was achieved for shifts > or =15 dB at one or more frequencies. CONCLUSIONS: An ototoxicity monitoring protocol that uses an individualized, one-octave range of frequencies tested in (1/6)-octave steps is quick to administer and has an acceptable FP rate. Similar test performance can be achieved using (1/3)-octave test frequencies, which further reduces monitoring test time. [ABSTRACT FROM AUTHOR]

Almost half of the population with multiple sclerosis (MS) complains of difficulty hearing, despite having essentially normal pure-tone thresholds. The purpose of the present investigation was to evaluate the effects of frequency-modulation (FM) technology utilization on speech perception in noise for adults with and without MS. Sentence material was presented at a constant level of 65 dBA Leq from a loudspeaker located at 0 degrees azimuth. The microphone of the FM transmitter was placed 7.5 cm from this loudspeaker. Multitalker babble was presented from four loudspeakers positioned at 45 degrees, 135 degrees, 225 degrees, and 315 degrees azimuths. The starting presentation level for the babble was 55 dBA Leq, The level of the noise was increased systematically in 1 dB steps until the subject obtained 0% key words correct on the IEEE (Institute for Electrical and Electronic Engineers) sentences. Test results revealed significant differences between the unaided and aided conditions at several signal-to-noise ratios. [ABSTRACT FROM AUTHOR]

The present investigation examined speech perception in noise of adults with and without multiple sclerosis (MS). Institute of Electrical and Electronic Engineers (IEEE) sentences were presented at a constant level of 65 dBA L[eq] (equivalent continuous noise level [4 dB exchange rate]) from a loudspeaker located at 0-degree horizontal azimuth and 1.2 m from the study participant. Uncorrelated multitalker babble was presented from four loudspeakers positioned at 45-, 135-, 225-, and 315-degree azimuths and 1.7 m from the study participant. The starting presentation level for the babble was 55 dBA L[eq]. The level of the babble was increased systematically in 1 dB steps until the subject obtained 0% key words correct on the IEEE sentences. Results revealed a significant difference in speech perception between the two groups at nine signal-to-noise ratios. Some clinical implications of these results are discussed. [ABSTRACT FROM AUTHOR]

Aminoglycoside antibiotics, commonly prescribed for adults and children to treat a wide range of bacterial infections, are potentially ototoxic, often causing irreversible damage to the auditory and vestibular systems. Ototoxic hearing loss usually begins at the higher frequencies and can progress to lower frequencies necessary for understanding speech. Individual susceptibility to aminoglycoside ototoxicity is determined by multiple physiologic and genetic factors. Children are especially vulnerable to ototoxic-induced damage, which can affect speech and language development even when limited to the high frequencies. Monitoring hearing loss during and after treatment by conventional and ultra-high frequency audiometry allows early detection of ototoxic hearing loss. Objective measures such as auditory brainstem responses (ABRs) and otoacoustic emissions (OAEs) can provide information about auditory function for individuals unable to provide reliable behavioral data, including young children. Early detection and subsequent alteration of treatment, as well as the potential future use of otoprotectants, may minimize or prevent ototoxic hearing loss. [ABSTRACT FROM AUTHOR]

Ototoxic hearing loss is usually detected earliest through monitoring of the highest audible frequencies in individuals administered ototoxic medications. Conducting ototoxicity monitoring may require testing patients in the hospital room. This study evaluated the use of insert earphones for obtaining reliable threshold responses at bedside. Twenty adult subjects were tested during two different sessions in the sound booth and on the ward. Thresholds were obtained for frequencies from 5 to 16 kHz and at 2 kHz with the use of the KOSS Pro/4X Plus earphones and Etymotic ER-4B MicroPro insert earphones. Results indicate that ER-4B insert earphones are as reliable as KOSS earphones for testing on the ward for high-frequency ototoxicity monitoring. [ABSTRACT FROM AUTHOR]

Effective objective HF (high-frequency) testing methodology provides for the early detection of ototoxic hearing loss because it typically progresses from high to low frequencies. Such early detection is considered necessary to prevent hearing loss from progressing into the frequency range important for understanding speech. Objective tests must be reliable, sensitive to hearing change, and time efficient. Auditory brainstem responses (ABRs) appear well suited to this task; however, current ABR techniques have limitations. Conventional clicks stimulate middle (1-4 kHz) rather than high frequencies (>8 kHz). Responses to HF tone bursts require considerable recording time. We hypothesized that using HF band-limited clicks (HF clicks) could overcome these limitations. Two different HF clicks, with bandwidths of 8-14 kHz were used to elicit ABRs. The current study compared responses among these stimuli. The results demonstrate the reliability of HF-click responses and of tone bursts presented in trains. [ABSTRACT FROM AUTHOR]

Clinical assessment of tinnitus usually includes pitch-matching between the tinnitus and a pure tone. Although such testing is performed routinely, response reliability has not been demonstrated yet. The present study continues a series of studies designed to develop automated methodology for quantifying tinnitus perceptual characteristics. Three methods for tinnitus pitch-matching were performed in a group of 42 subjects. Two methods were computer-automated (Binary and Subject-Guided) and the third method was a traditional manual technique. Each method provided excellent response reliability for about half of the subjects. The most reliable subjects, however, differed widely between the different methods. Each subject provided a total of 14 pitch matches using the three different methods. Analyses based on each subject's total of 14 pitch matches revealed the range of pitch matches for each subject. About half of the subjects selected pitch matches over a range of 2 1/3 octaves. Results of this study suggest that specifying the range of tinnitus pitch matches rather than attempting to identify a single pitch match may be more appropriate. [ABSTRACT FROM AUTHOR]

This paper describes the second phase of a study to determine test-retest reliability of hearing thresholds using a computer-automated technique with ER-4B Canal Phone insert earphones. The first phase documented reliable hearing thresholds in 20 normal-hearing individuals. For this second phase, 20 individuals with cochlear hearing loss completed the same testing protocol as for phase one. During each of two sessions, hearing thresholds were obtained in one-third octave steps at 500 Hz to 16,000 Hz. The octave frequencies were immediately retested, followed by ear-tip reinsertion and further retesting at octave frequencies. Both groups showed overall good threshold reliability, with observable differences between groups. First, repeated testing resulted in improved hearing thresholds for the normal-hearing group, but not for the cochlear-loss group. Second, the normal-hearing group showed overall better response reliability, both within and between sessions, than the cochlear-loss group. These differences were small but consistent. [ABSTRACT FROM AUTHOR]

Tinnitus Retraining Therapy (TRT) is a structured method of tinnitus treatment that has been performed since 1990. The TRT Initial Interview form was developed to guide clinicians in obtaining essential information from patients that would specify treatment needs. The TRT Follow-up Interview form is similar to the initial interview form and is designed to evaluate outcomes of treatment. The clinician administers these forms verbally. The forms have been used in a highly abbreviated format with the potential for inconsistent interview administration between examiners. This project was to expand the forms to provide specific wording for each question. The expanded forms are presented in this article, and the intent of each question is explained. Standardized administration of these interview forms will facilitate greater uniformity in the initial evaluation and outcomes analyses of patients treated with TRT. [ABSTRACT FROM AUTHOR]

Clinical management for patients complaining of severe tinnitus has improved dramatically in the last 25 years. During that period of time, various methods of treatment have been introduced and are being used with varying degrees of success. One method that has received considerable attention is tinnitus retraining therapy (TRT). This method is being practiced by hundreds of clinicians worldwide, and retrospective clinical data indicate that TRT has been effective for the majority of patients. This article provides a guide for clinicians to evaluate their patients for treatment with TRT. Included in this guide is the expanded version of the TRT initial interview and specific instructions for the clinician administering the interview. [ABSTRACT FROM AUTHOR]

Two methods for treating tinnitus are compared. Tinnitus masking has been used for over 25 years, and although this method is used in clinics around the world, there are many misconceptions regarding the proper protocol for its clinical application. Tinnitus retraining therapy has been used clinically for over 12 years and has received considerable international attention. Although these methods are distinctive in their basic approach to tinnitus management, certain aspects of treatment appear similar. These aspects of treatment have created considerableconfusion and controversy, especially regarding the use of 'sound therapy' as a basic component of treatment. It is the objective of this article to clarify the major differences that exist between these two forms of treatment. [ABSTRACT FROM AUTHOR]

Speech understanding deficits are common in older adults. In addition to hearing sensitivity, changes in certain cognitive functions may affect speech recognition. One such change that may impact the ability to follow a rapidly changing speech signal is processing speed. When speakers slow the rate of their speech naturally in order to speak clearly, speech recognition is improved. The acoustic characteristics of naturally slowed speech are of interest in developing time-expansion algorithms to improve speech recognition for older listeners. In this study, we tested younger normally hearing, older normally hearing, and older hearing-impaired listeners on time-expanded speech using increased duration and increased intensity of unvoiced consonants. Although all groups performed best on unprocessed speech, performance with processed speech was better with the consonant gain feature without time expansion in the noise condition and better at the slowest time-expanded rate in the quiet condition. The effects of signal processing on speech recognition are discussed. [ABSTRACT FROM AUTHOR]

Clinical assessment of the perceptual characteristics of tinnitus usually includes an attempt to match the pitch of tinnitus to a pure tone. A standardized clinical protocol for tinnitus pitch matching does not yet exist, and there is a history of unsuccessful attempts to obtain such measures reliably. The present study was designed to evaluate new protocols for identifying the perceived pitch of tinnitus, with the objectives of reducing testing time and improving test-retest reliability. Two protocols ('Octave' and 'Binary') were developed, each of which was patterned after the testing procedure previously developed at the Oregon Tinnitus Clinic and used to assess thousands of tinnitus patients. Both protocols use computer-automation to conduct testing; the protocols differ according to their specific testing algorithms. Twenty subjects with nonfluctuating tinnitus were each tested over two sessions. Results of testing revealed that both protocols could obtain pitch matches within 20 to 25 min. Reliability of responses was good for some subjects but not others, and the Binary protocol generally provided more reliable results. [ABSTRACT FROM AUTHOR]

This study was conducted to document test-retest reliability of hearing thresholds using our computer-automated tinnitus matching technique and Etymotic ER-4B Canal Phone insert earphones. The research design involved repeated threshold measurements both within and between sessions, and testing to evaluate the potential effect of eartip removal and reinsertion. Twenty normal-hearing subjects were evaluated over two testing sessions with the use of a fully automated protocol for determining thresholds with 1-dB precision. Thresholds were first obtained at 0.5-16.0 kHz, in one-third octave frequency steps (16 test frequencies). The octave frequencies were then retested, first without removing the eartips, then after eartip removal and replacement. Responses between sessions differed by an average of 2.5 dB across all 16 test frequencies, and 91.5 percent of the repeated thresholds varied within +/-5 dB (98.1 percent within +/-10 dB). Reliability of within-sessions thresholds was also good, and there was no effect of eartip removal and replacement. [ABSTRACT FROM AUTHOR]

Cancer treatment often requires patients to be exposed to drugs that can damage hearing. Drugs such as cisplatin can cause permanent damage to hearing if not detected early. Damage typically occurs first in the more basal regions of the cochlea which are specific for high-frequency (HF) hearing and progresses to more apical regions that are relevant to speech understanding. Monitoring of HF hearing loss can be an effective means for early detection of ototoxicity caused by chemotherapy. Once ototoxicity is detected, the oncology medical team could adjust the drug dosage or switch to medications that are less ototoxic. Telehealth technology may improve access to ototoxicity monitoring. Patients could monitor their own hearing using a device that alerts healthcare professionals in the event of a change in hearing. A portable audiometer is currently not available that is 1) capable of automatic or manual (by an audiologist) operation; 2) designed with precision pure-tone functionality up to 20 kHz; and 3) able to remotely transfer health status information to a healthcare professional. This paper describes the design of a technology, the ototoxicity identification (OtoID), that includes a portable audiometer with HF test functionality that meets ANSI/ASA S3.6-2010 standards and is capable of reliably detecting a person's drug-related hearing changes relative to a baseline period (i.e., before ototoxic drugs) using an automated test. The system includes a wireless cellular modem capable of notifying a remote healthcare professional in the event that a significant change in hearing has occurred in the patient. The system was evaluated on test subjects within a sound-proof booth, a noisy hospital ward, and within their homes. Results indicate that the OtoID system can be used by patients to effectively monitor hearing changes remotely within their home or in a hospital ward, ultimately enabling early detection of ototoxicity and potentially avoiding hearing loss.

Background: Cisplatin is effective in the treatment of several cancers but is a known ototoxin resulting in shifts to hearing sensitivity in up to 50-60% of patients. Cisplatin-induced hearing shifts tend to occur first within an octave of a patient's high frequency hearing limit, termed the sensitive range for ototoxicity (SRO), and progress to lower frequencies. While it is currently not possible to know which patients will experience ototoxicity without testing their hearing directly, monitoring the SRO provides an early indication of damage. A tool to help forecast susceptibility to ototoxic-induced changes in the SRO in advance of each chemotherapy treatment visit may prove useful for ototoxicity monitoring efforts, patient counseling, and therapeutic planning., Purpose: This project was designed to (1) establish pretreatment risk curves that quantify the probability that a new patient will suffer hearing loss within the SRO during treatment with cisplatin and (2) evaluate the accuracy of these predictions in an independent sample of Veterans receiving cisplatin for the treatment of cancer., Study Sample: Two study samples were used. The Developmental sample contained 23 subjects while the Validation sample consisted of 12 subjects., Data Collection and Analysis: Risk curve predictions for SRO threshold shifts following cisplatin exposure were developed using a Developmental sample comprised of data from a total of 155 treatment visits obtained in 45 ears of 23 Veterans. Pure-tone thresholds were obtained within each subject's SRO at each treatment visit and compared with baseline measures. The risk of incurring an SRO shift was statistically modeled as a function of factors related to chemotherapy treatment (cisplatin dose, radiation treatment, doublet medication) and patient status (age, pre-exposure hearing, cancer location and stage). The model was reduced so that only statistically significant variables were included. Receiver-operating characteristic (ROC) curve analyses were then used to determine the accuracy of the risk curve predictions in an independent Validation sample of observations from over 62 treatment visits obtained in 24 ears of 12 Veterans., Results: Only cumulative cisplatin dose and pre-exposure hearing were found to be significantly related to the risk for hearing shift. The dose-ototoxicity risk curve predictions developed from the Developmental sample yielded area under the ROC curve accuracy estimates of 0.85 when applied to an independent Validation sample., Conclusions: Cumulative cisplatin dose in combination with pre-exposure hearing provides an indication of whether hearing will shift in the SRO in advance of cisplatin administration. The validated dose-ototoxicity risk curves described herein can be used before and during treatment to anticipate hearing loss. While having such a tool would not replace serial hearing testing, it would be of great benefit to an ototoxicity monitoring program. It would promote relevant pretreatment counseling. Furthermore, for those found to be at risk of SRO shifts within the speech frequencies, the oncology treatment plan could incorporate anticipated dosing adjustments that could stave off the impact that ototoxicity might bring., (American Academy of Audiology.)

Stimulus-frequency (SF) otoacoustic emission (OAE) amplitude and the amplitude of medial olivocochlear (MOC) inhibition of SF OAEs for ipsilateral, contralateral and bilateral MOC reflex elicitors were recorded in six subjects with type 2 diabetes during a glucose tolerance test (GTT). Five of the six subjects were tested twice for a total of 11 trials and three subjects were tested in a control experiment. During the GTT experiment, the subjects' blood glucose was elevated from a euglycemic level below 150 mg/dL to a hyperglycemic level above 160 mg/dL following the consumption of a bolus of 80 g of sugar. A subset of three subjects were tested in a control experiment during which SF OAE and MOC reflex measurements were made while blood sugar levels remained constant within the euglycemic region. Mean SF OAE amplitudes were elevated following glucose consumption. A statistically significant increase in MOC inhibition amplitude was observed during elevated sugar levels for the 11 GTT trials. Maximum inhibition occurred about an hour after glucose consumption when blood glucose levels peaked. Results indicate that acute hyperglycemia influences efferent control of the cochlea in people with type 2 diabetes.

Thirty-six blast-exposed patients and twenty-nine non-blast-exposed control subjects were tested on a battery of behavioral and electrophysiological tests that have been shown to be sensitive to central auditory processing deficits. Abnormal performance among the blast-exposed patients was assessed with reference to normative values established as the mean performance on each test by the control subjects plus or minus two standard deviations. Blast-exposed patients performed abnormally at rates significantly above that which would occur by chance on three of the behavioral tests of central auditory processing: the Gaps-In-Noise, Masking Level Difference, and Staggered Spondaic Words tests. The proportion of blast-exposed patients performing abnormally on a speech-in-noise test (Quick Speech-In-Noise) was also significantly above that expected by chance. These results suggest that, for some patients, blast exposure may lead to difficulties with hearing in complex auditory environments, even when peripheral hearing sensitivity is near normal limits.

Purpose: This cross-sectional study had two goals: (1) Identify and quantify the effects of aging on the auditory brainstem response (ABR); (2) Describe how click rate and hearing impairment modify effects of aging. RESEARCH DESIGN AND ANALYSIS: ABR measures were obtained from 131 predominately male Veteran participants aged 26 to 71 yr. Metrics analyzed include amplitude and latency for waves I, III, and V, and the I-V interpeak latency interval (IPI) at three repetition rates (11, 51, and 71 clicks/sec) using both polarities. In order to avoid confounding from missing data due to hearing impairment, participants had hearing thresholds <40 dB HL at 2 kHz and 70 dB HL at 4 kHz in at least one ear. Additionally, the median 2, 3, and 4 kHz pure tone threshold average (PTA2,3,4) for the sample, ∼17 dB HL, was used to delineate subgroups of better and worse hearing ears, and only the better hearing sample was modeled statistically. We modeled ABR responses using age, repetition rate, and PTA2,3,4 as covariates. Random effects were used to model correlation between the two ears of a subject and across repetition rates. Inferences regarding effects of aging on ABR measures at each rate were derived from the fitted model. Results were compared to data from subjects with poorer hearing., Results: Aging substantially diminished amplitudes of all of the principal ABR peaks, largely independent of any threshold differences within the group. For waves I and III, age-related amplitude decrements were greatest at a low (11/sec) click rate. At the 11/sec rate, the model-based mean wave III amplitude was significantly smaller in older compared with younger subjects even after adjusting for wave I amplitude. Aging also increased ABR peak latencies, with significant shifts limited to early waves. The I-V IPI did not change with age. For both younger and older subjects, increasing click presentation rate significantly decreased amplitudes of early peaks and prolonged latencies of later peaks, resulting in increased IPIs. Advanced age did not enhance effects of rate. Instead, the rate effect on wave I and III amplitudes was attenuated for the older subjects due to reduced peak amplitudes at lower click rates. Compared with model predictions from the sample of better hearing subjects, mean ABR amplitudes were diminished in the group with poorer hearing, and wave V latencies were prolonged., Conclusions: In a sample of veterans, aging substantially reduced amplitudes of all principal ABR peaks, with significant latency shifts limited to waves I and III. Aging did not influence the I-V IPI even at high click rates, suggesting that the observed absolute latency changes associated with aging can be attributed to changes in auditory nerve input. In contrast, ABR amplitude changes with age are not adequately explained by changes in wave I. Results suggest that aging reduces the numbers and/or synchrony of contributing auditory nerve units. Results also support the concept that aging reduces the numbers, though perhaps not the synchrony, of central ABR generators., (American Academy of Audiology.)

Auditory system functions, from peripheral sensitivity to central processing capacities, are all at risk from a blast event. Accurate encoding of auditory patterns in time, frequency, and space are required for a clear understanding of speech and accurate localization of sound sources in environments with background noise, multiple sound sources, and/or reverberation. Further work is needed to refine the battery of clinical tests sensitive to the sorts of central auditory dysfunction observed in individuals with blast exposure. Treatment options include low-gain hearing aids, remote-microphone technology, and auditory-training regimens, but clinical evidence does not yet exist for recommending one or more of these options. As this population ages, the natural aging process and other potential brain injuries (such as stroke and blunt trauma) may combine with blast-related brain changes to produce a population for which the current clinical diagnostic and treatment tools may prove inadequate. It is important to maintain an updated understanding of the scope of the issues present in this population and to continue to identify those solutions that can provide measurable improvements in the lives of Veterans who have been exposed to high-intensity blasts during the course of their military service.

Introduction: A nonbehavioral method for monitoring ototoxicity in patients treated with cisplatin is needed because patients enduring chemotherapy may not be well or cooperative enough to undergo repeated hearing tests. Distortion-product otoacoustic emissions (DPOAEs) provide a nonbehavioral measure of auditory function that is sensitive to cisplatin exposure. However, interpreting DPOAE findings in the context of ototoxicity monitoring requires that their accuracy be determined in relation to a clinically accepted gold standard test., Objectives: Among patients receiving cisplatin for the treatment of cancer, we sought to (1) identify the combination of DPOAE metrics and ototoxicity risk factors that best classified ears with and without ototoxic-induced hearing changes; and (2) evaluate the test performance achieved by the composite measure as well as by DPOAEs alone., Design: Odds of experiencing hearing changes at a given patient visit were determined using data collected prospectively from 24 Veterans receiving cisplatin. Pure-tone thresholds were examined within an octave of each subject's high-frequency hearing limit. DPOAE were collected as a set of four response growth (input/output) functions near the highest f2 frequency that yielded a robust response at L2 = L1 = 65 dB SPL. Logistic regression modeled the risk of hearing change using several DPOAE metrics, drug treatment factors, and other patient factors as independent variables. An optimal discriminant function was derived by reducing the model so that only statistically significant variables were included. Receiver operating characteristic curve analyses were used to evaluate test performance., Results: At higher cisplatin doses, ears with better hearing at baseline were more likely to exhibit ototoxic hearing changes than those with poorer hearing. Measures of pre-exposure hearing, cumulative drug dose, and DPOAEs generated a highly accurate discriminant function with a cross-validated area under the receiver operating characteristic curve of 0.9. DPOAEs alone also provided an indication of ototoxic hearing change when measured at the highest DPOAE test frequency that yielded a robust response., Conclusions: DPOAEs alone and especially in combination with pre-exposure hearing and cisplatin dose provide an indication of whether or not hearing has changed as a result of cisplatin administration. These promising results need to be validated in a separate sample.

An objective method for identifying ototoxic hearing loss among patients receiving cisplatin is necessary since the ability of patients to take a behavioral test may change over the course of treatment. Data from 56 monitoring visits by 19 Veterans taking cisplatin were used to identify combinations of distortion-product otoacoustic emission (DPOAE) metrics and ototoxicity risk factors that best identified ototoxic hearing loss. Models were tested that incorporated DPOAE metrics generated statistically using partial least-squares analysis. Models were also tested that incorporated a priori DPOAE change criteria, such as a minimum DPOAE level shift of 6 dB. Receiver Operating Characteristic analysis was used to compare the accuracy of these models. The best performing model incorporated weighted combinations of pre-treatment hearing, cumulative cisplatin dose and DPOAE metrics that were determined using partial least-squares and evaluated over a quarter octave range near each subjects' high frequency DPOAE limit. Using this model and the DPOAE recording methods described herein, the chance of ototoxic hearing change can be determined at any given observed change in DPOAE level. This approach appears to provide an accurate and rapid ototoxicity risk assessment (ORA) that once validated can be used clinically.

Background and Purpose: To report on the incidence and relative risk of tinnitus onset from a variety of drug therapies known to be ototoxic. Two main questions were asked: (1) What is the prevalence and incidence of tinnitus among patients treated with cisplatin, carboplatin, or ototoxic antibiotic therapies? (2) Do commonly reported treatment or subject factors confound or modify the incidence of tinnitus onset?, Data Collection and Analysis: A prospective observational study design was used to evaluate occurrence of significant otologic changes in 488 veterans (962 ears) receiving chemotherapeutic agents (cisplatin, carboplatin), ototoxic antibiotics (primarily aminoglycoside), or nonototoxic drugs (control medications). A subset of 260 veterans lacking tinnitus prior to drug exposure was used to compare rates of tinnitus onset. Subjects were tested prior to, during, and following their treatment. Planned comparisons using logistic regression, analysis of variance (ANOVA), and chi(2) statistics were made among groups by the type of medication taken, age, presence of preexisting hearing loss, days on drug, and cumulative dose of drug., Results: Baseline tinnitus rates were high (nearly 47%) relative to the general population of a similar age. Subjects with exposure to ototoxic medications had significantly increased risk for developing tinnitus. Those on chemotherapeutic agents were found to have the greatest risk. Cisplatin elevated the risk by 5.53 times while carboplatin increased the risk by 3.75 over nonototoxic control medications. Ototoxic antibiotics resulted in borderline risk (2.81) for new tinnitus. Contrary to other reports, we did not find that subject factors (increased age or pre-existing hearing loss) or treatment factors (days on drug or cumulative dose) contributed to rates of tinnitus onset during treatment., Conclusions: This large prospective study confirms that new tinnitus during treatment is associated with chemotherapy and with certain ototoxic antibiotic treatment. Cisplatin and carboplatin were found to be the most potent ototoxic agents causing tinnitus at much greater numbers than the other drugs studied. Implications for counseling and audiological resource allocation are discussed., (American Academy of Audiology.)

The purpose of the present investigation was to determine whether differences exist in audiometric hearing status between individuals with and without multiple sclerosis (MS) and between individuals with relapsing-remitting MS (RRMS) and individuals with secondary progressive MS (SPMS). Forty-seven subjects with MS (26 with RRMS and 21 with SPMS) and forty-nine control subjects without MS completed both a comprehensive case-history questionnaire and a conventional hearing evaluation. Statistical analyses, accounting for the potential confounding factors of age, sex, noise exposure, and use of ototoxic medications, revealed significant differences in hearing thresholds between subjects with and without MS at select audiometric test frequencies (p < 0.05). At these audiometric test frequencies, the subjects with MS had poorer hearing thresholds. Additional analyses revealed significant differences in hearing sensitivity at select audiometric frequencies between the subjects with RRMS and the subjects with SPMS, such that those with SPMS had poorer hearing thresholds. These findings have significant clinical implications for practitioners working with patients with MS.

The dramatic escalation of blast exposure in military deployments has created an unprecedented amount of traumatic brain injury (TBI) and associated auditory impairment. Auditory dysfunction has become the most prevalent individual service-connected disability, with compensation totaling more than 1 billion dollars annually. Impairment due to blast can include peripheral hearing loss, central auditory processing deficits, vestibular impairment, and tinnitus. These deficits are particularly challenging in the TBI population, as symptoms can be mistaken for posttraumatic stress disorder, mental-health issues, and cognitive deficits. In addition, comorbid factors such as attention, cognition, neuronal loss, noise toxicity, etc., can confound assessment, causing misdiagnosis. Furthermore, some auditory impairments, such as sensorineural hearing loss, will continue to progress with age, unlike many other injuries. In the TBI population, significant clinical challenges are the accurate differentiation of auditory and vestibular impairments from multiple, many times overlapping, symptoms and the development of multidisciplinary rehabilitation strategies to improve treatment outcomes and quality of life for these patients.

The development and digital waveform synthesis of a multiple-frequency tone-burst (MFTB) stimulus is presented. The stimulus is designed to improve the efficiency of monitoring high-frequency auditory-brainstem-response (ABR) hearing thresholds. The pure-tone-based, fractional-octave-bandwidth MFTB supports frequency selective ABR audiometry with a bandwidth that falls between the conventional click and single-frequency tone-burst stimuli. The MFTB is being used to identify high frequency hearing threshold change due to ototoxic medication which most generally starts at the ultra-highest hearing frequencies and progresses downwards but could be useful in general limited-bandwidth testing applications. Included is a Mathcad implementation and analysis of our MFTB synthesis technique and sample performance measurements of the MFTB stimulus configuration used in a clinical research ABR system.

Background: Effective screening programs should not merely detect presence of disease, but also lead to long-term benefit. We describe the rationale and design of the first randomized clinical trial to study the long-term effects of routine screening for hearing loss. We also describe the baseline characteristics of the randomized cohort., Methods: We randomized 2305 veterans age 50 years or older to a control arm without screening, or to screening with: physiologic testing (AudioScope), a self-administered questionnaire (Hearing Handicap Inventory for the Elderly-Screening version [HHIE-S]), or both tests. The primary outcome measure will be hearing aid use one year after screening. We will also study a number of secondary outcomes, including appointments made with and visits to an audiologist, cases of aidable hearing loss, hearing aids dispensed, self-rated communication ability, and hearing-related quality of life., Results: Baseline demographic and health status measures were evenly distributed across the screening arms. The percentage of patients who screened positive for hearing loss was 18.6%, 59.2%, and 63.6% for the AudioScope, HHIE-S, and combined screening arms, respectively., Implications: Long-term results are needed to gain insight into whether the AudioScope is associated with high rates of false negative screening, the HHIE-S is associated with high rates of false positive screening, or a combination of both. Identifying the best screening program will depend on determining which strategy leads to successful hearing aid use.

Clinicians and patients need mobile tools to detect ototoxic change early and prevent hearing loss. We report on the development of an upgrade of our existing desktop-based clinical-audiological instrumentation into a mobile instrument platform which efficiently supports personalized ototoxicity monitoring on the hospital wards as well as clinic by a trained clinician. Our new wireless-enabled system also serves as the instrumentation platform for the next phase of our work which is remote healthcare delivery with patient-guided at-home ototoxicity monitoring using an evidence-based individualized SRO protocol.

Context: Numerous studies have demonstrated that hearing aids provide significant benefit for a wide range of sensorineural hearing loss, but no carefully controlled, multicenter clinical trials comparing hearing aid efficacy have been conducted., Objective: To compare the benefits provided to patients with sensorineural hearing loss by 3 commonly used hearing aid circuits., Design: Double-blind, 3-period, 3-treatment crossover trial conducted from May 1996 to February 1998., Setting: Eight audiology laboratories at Department of Veterans Affairs medical centers across the United States., Patients: A sample of 360 patients with bilateral sensorineural hearing loss (mean age, 67.2 years; 57% male; 78.6% white)., Intervention: Patients were randomly assigned to 1 of 6 sequences of linear peak clipper (PC), compression limiter (CL), and wide dynamic range compressor (WDRC) hearing aid circuits. All patients wore each of the 3 hearing aids, which were installed in identical casements, for 3 months., Main Outcome Measures: Results of tests of speech recognition, sound quality, and subjective hearing aid benefit, administered at baseline and after each 3-month intervention with and without a hearing aid. At the end of the experiment, patients ranked the 3 hearing aid circuits., Results: Each circuit markedly improved speech recognition, with greater improvement observed for soft and conversationally loud speech (all 52-dB and 62-dB conditions, P

This study addresses the need for uniformity in techniques for clinical quantification of tinnitus. Because automation can be an effective means to achieve standardization, this laboratory is developing techniques to perform computer-automated tinnitus testing. The present study was conducted to demonstrate the feasibility of obtaining reliable tinnitus measures using a fully automated system. A computer-controlled psychoacoustical system was developed to quantify tinnitus loudness and pitch using a tone-matching technique. Hearing thresholds were also obtained as part of the procedure. The system generated test stimuli and simultaneously controlled a notebook computer positioned in the sound chamber facing the patient. The notebook computer displayed instructions for responding and relayed response choices through on-screen "buttons" that the patient touched with a pen device. Twenty individuals with tinnitus were evaluated with the technique over two sessions, and responses were analyzed for test-retest reliability. Analyses revealed good reliability of thresholds, loudness matches, and pitch matches. These results demonstrate that use of a fully automated system to obtain reliable measurements of tinnitus loudness and pitch is feasible for clinical application.

This study addressed the clinical need to obtain frequency-specific auditory brainstem responses (ABRs) more rapidly than is currently possible. ABRs were obtained from 20 subjects using two different methods: a conventional method with tone bursts presented singly and a multiple-stimulus method using a train of 20 tone bursts. For both methods, tone bursts were presented at frequencies 1, 2, 4, and 8 kHz, shaped with a Blackman-Harris window and having intensity levels up to 105 dB peak equivalent sound pressure level (peSPL). The single tone bursts were presented at a 17.2/sec repetition rate. The 20 tone-burst train used the four frequencies at five intensities each and a repetition rate of 3.7/sec (separations between tone bursts of 9-12 msec, with 77 msec off-time between trains). Mean latencies and mean amplitudes for wave V were compared using t-tests for each of 12 conditions (four frequencies, each at the three highest output levels). For latency, only one comparison was significantly different (2 kHz, 77 dB peSPL). Similarly, only one comparison was significant for amplitude (2 kHz, 97 dB peSPL). There was, however, a trend for the tone bursts presented in trains to have longer latencies and reduced amplitudes compared to the respective responses for the single tone-burst condition. These results indicate the presence of some response adaptation when tone bursts are presented in a train. The use of a properly designed stimulus train can result in a significant time savings for obtaining frequency-specific ABRs as compared with single tone-burst presentations.

Repeated tinnitus loudness matches (LMs) were obtained to determine response reliability using a computer-automated technique with two procedural variations, fixed or random step sizes, to increase output level during the initial ascending series of tones at each frequency. Twenty subjects with stable, tonal tinnitus were evaluated with both methods during each of two sessions. Response instructions were displayed on a portable computer, and a pen device was used to make response choices that appeared on the touch-sensitive video monitor. For each method, hearing thresholds and LMs were obtained, with 1-dB resolution, at 1/3-octave frequencies from 1 to 16 kHz. Analyses revealed reliability of LMs to be equivalent between methods. LM data are reported in both dB SPL and dB SL, with the SPL values providing greater reliability both within and between sessions (all r's > or = .889, p's < or = .0001).

Retrospective analysis of hearing-threshold data from a multisite ototoxicity monitoring study identified an individualized range of predominantly high frequencies (> 8 kHz) that appeared to be highly sensitive to early threshold changes caused by ototoxicity. This suggested the potential for a limited-frequency monitoring protocol that could be conducted rapidly without compromising sensitivity to ototoxicity. Such testing would require high-frequency thresholds to be obtained independently, that is, without prior testing at conventional frequencies (0.25-8 kHz). This study was conducted to determine the test-retest reliability of isolated threshold testing in a "target" frequency range of high frequencies (9, 10, 11.2, 12.5, and 14 kHz) that represented a shortened ototoxicity monitoring test. Twenty normal-hearing subjects were evaluated over five sessions. During each session, subjects were tested in each of two conditions: (1) conventional frequencies (0.25-8 kHz) tested first, followed by target frequencies; and (2) target frequencies tested alone (isolation condition). Depending on test frequency, reliability of high-frequency thresholds was either unchanged or improved in the isolation condition. Although these results cannot be generalized to ill hospitalized patients, who may also have pre-existing hearing loss, they lay the groundwork for development of a time-saving limited-frequency test to monitor for ototoxicity in these patients.

An auditory brainstem response method is described for evoking responses to 4 high-frequency (8, 10, 12 and 14 kHz) tonebursts in the same amount of time normally required to obtain responses to single tonebursts. Reliability of responses to high-frequency toneburst stimuli presented in the conventional manner (one at a time) has been previously documented. In the present study, high-frequency tonebursts were presented to 20 normal-hearing subjects singly and in a 4-stimulus sequence. The reliability of resulting responses did not differ significantly between single- and multiple-stimulus test conditions. It is concluded that this sequenced-stimulus concept could be developed for use in serial monitoring of individuals receiving ototoxic agents as well as being broadly applicable to clinical situations in which patients cannot or will not respond voluntarily.