Michael Valente

Clinical Practice Guideline: Sudden Hearing Loss

Objective. Sudden hearing loss (SHL) is a frightening symptom that often prompts an urgent or emergent visit to a physician. This guideline provides evidence-based recommendations for the diagnosis, management, and follow-up of patients who present with SHL. The guideline primarily focuses on sudden sensorineural hearing loss (SSNHL) in adult patients (aged 18 and older). Prompt recognition and management of SSNHL may improve hearing recovery and patient quality of life (QOL). Sudden sensorineural hearing loss affects 5 to 20 per 100,000 population, with about 4000 new cases per year in the United States. This guideline is intended for all clinicians who diagnose or manage adult patients who present with SHL. Purpose. The purpose of this guideline is to provide clinicians with evidence-based recommendations in evaluating patients with SHL, with particular emphasis on managing SSNHL. The panel recognized that patients enter the health care system with SHL as a nonspecific, primary complaint. Therefore, the initial recommendations of the guideline deal with efficiently distinguishing SSNHL from other causes of SHL at the time of presentation. By focusing on opportunities for quality improvement, the guideline should improve diagnostic accuracy, facilitate prompt intervention, decrease variations in management, reduce unnecessary tests and imaging procedures, and improve hearing and rehabilitative outcomes for affected patients. Results. The panel made strong recommendations that clinicians should (1) distinguish sensorineural hearing loss from conductive hearing loss in a patient presenting with SHL; (2) educate patients with idiopathic sudden sensorineural hearing loss (ISSNHL) about the natural history of the condition, the benefits and risks of medical interventions, and the limitations of existing evidence regarding efficacy; and (3) counsel patients with incomplete recovery of hearing about the possible benefits of amplification and hearing-assistive technology and other supportive measures. The panel made recommendations that clinicians should (1) assess patients with presumptive SSNHL for bilateral SHL, recurrent episodes of SHL, or focal neurologic findings; (2) diagnose presumptive ISSNHL if audiometry confirms a 30-dB hearing loss at 3 consecutive frequencies and an underlying condition cannot be identified by history and physical examination; (3) evaluate patients with ISSNHL for retrocochlear pathology by obtaining magnetic resonance imaging, auditory brainstem response, or audiometric follow-up; (4) offer intratympanic steroid perfusion when patients have incomplete recovery from ISSNHL after failure of initial management; and (5) obtain follow-up audiometric evaluation within 6 months of diagnosis for patients with ISSNHL. The panel offered as options that clinicians may offer (1) corticosteroids as initial therapy to patients with ISSNHL and (2) hyperbaric oxygen therapy within 3 months of diagnosis of ISSNHL. The panel made a recommendation against clinicians routinely prescribing antivirals, thrombolytics, vasodilators, vasoactive substances, or antioxidants to patients with ISSNHL. The panel made strong recommendations against clinicians (1) ordering computerized tomography of the head/brain in the initial evaluation of a patient with presumptive SSNHL and (2) obtaining routine laboratory tests in patients with ISSNHL.

The Independent Hearing Aid Fitting Forum (IHAFF) Protocol.

The Independent Hearing Aid Fitting Forum (IHAFF) protocol was developed between 1993 and 1994 during numerous weekend meetings in Denver, Tampa, Anaheim and Chicago. The protocol was the brainchild of Dennis Van Vliet and Michael Marion, who were frustrated by the gap between the ever-evolving technology and the tools available for selecting, fitting and verifying the performance of hearing aids. As clinicians, they were concerned that there was a general lack of knowledge on how to appropriately determine if their patient was a better candidate for wide dynamic range compression, compression limiting, or compression in which the compressor is activated at an intermediate level. Further, they were concerned about the decisions that clinicians were being asked to make everyday which did not need to be made just a few years ago. For example, how to appropriately adjust the compression ratio (CR), compression kneepoint (KP), release time or output in one or more channels. In addition, they were concerned that the present prescriptive formulas, which are appropriate when fitting linear hearing aids, are not appropriate when fitting hearing aids with nonlinear signal processing. Finally, Dennis and Michael did not see any activity when attending professional meetings or reading professional journals which gave them any hope that relief for their concerns was forthcoming. Due to these concerns, Michael and Dennis believed that it was necessary to gather colleagues together who might be able to develop a protocol to help clinicians better serve their patients when dispensing hearing aids containing both linear and nonlinear signal processing. The members of the IHAFF committee were Lucille Beck, Ruth Bentler, Robyn Cox, David Fabry, Gail Gudmundsen, David Hawkins, Mead Killion, Michael Marion, Gus Mueller, Larry Revit, Michael Valente and Dennis Van Vliet. Margo Skinner was an early member of the committee but had to leave because of other commitments. As the reader can imagine, the discussions at these meetings were stimulating, challenging, intriguing, heated and controversial. Numerous fitting and verification strategies were discussed and discarded for a variety of reasons. For example, early discussions centered around referencing all measurements (threshold and loudness judgments) to dB SPL near the eardrum (i.e., SPL-O-GRAM). However, this idea was dropped because equipment was not available to perform these tasks in a clinically efficient manner at the time of the discussions. As the reader knows, such equipment is now available (i.e., the Madsen Auracle, Etymonic Designs AudioScan, Starkey Pro-Connect, ReSounds Real Ear Loudness Mapping (RELM) and Frye real ear analyzers). Discussions were also especially prolonged around the issue of “predicting” loudness judgments from threshold as opposed to individual measurement of loudness judgments. The final IHAFF protocol requires individual measurement of loudness scaling. Important considerations such as counseling, fine-tuning, aural rehabilitation, assistive listening devices, directional microphones, remote controls or digital volume controls were discussed, but it was decided not to include these issues in the final document. The result of those meetings, phone calls, faxes and e-mail messages is the IHAFF protocol. The primary goal of the IHAFF protocol is to “normalize” the loudness experiences of the hearing-impaired patient. Specifically, the goals of the IHAFF protocol are: Sounds judged as “soft” by a normal listener should be audible and judged as “soft” by a hearing-impaired listener who is wearing hearing aids. Sounds judged as “comfortable” by a normal listener should be judged as “comfortable” by a hearing-impaired listener who is wearing hearing aids. Sounds judged as “loud” by a normal listener should be judged as “loud”, but not “uncomfortably loud” by a hearing-impaired listener who is wearing hearing aids. Also, to prevent amplified sounds from exceeding the users uncomfortable loudness level (LDL). Typically for a cochlear-impaired listener, the use of compression and more than one processing channel will be needed to reach these goals. That is, less gain would be supplied at the higher input levels (compression) if the patient exhibits loudness recruitment, and greater compression might well be needed in the high frequency region where typically the dynamic range between threshold and UCL is reduced in comparison to the dynamic range in the low frequency region. This issue of Trends in Amplification is dedicated to providing the reader with a better knowledge of how to implement the IHAFF protocol. The manuscript is divided into two sections. The first section describes, in detail, how to operate the software that has been developed to assist the user to implement the IHAFF protocol. The second section illustrates the implementation of the IHAFF protocol by “walking through” the entire process with one of our patients.

Use of Microphone Technology to Improve User Performance in Noise

Because of the improvement in SNR reported for dual microphones in the studies reviewed in this manuscript, it is felt that a greater number of manufacturers will be releasing producis containing dual-microphone technology in the near future. For example, at the time this manuscript was prepared, Siemens, ReSound and Danavox introduced dual-microphone BTE and ITE hearing aids with DSP. Micro-Tech also recently releascd an ITE with dual microphones. Oticon recently introduced an ITE with DSP and a D-Mic™. It is clear that more manufacturers will introduce hearing aids with dual microphones or the D-Mic™ in the years ahead.

Unaided and aided performance with a directional open-fit hearing aid.

Differences in performance between unaided and aided performance (omnidirectional and directional) were measured using an open-fit behind-the-ear (BTE) hearing aid. Twenty-six subjects without prior experience with amplification were fitted bilaterally using the manufacturers recommended procedure. After wearing the hearing aids for one week, the fitting parameters were fine-tuned, based on subjective comments. Four weeks later, differences in performance between unaided and aided (omnidirectional and directional) were assessed by measuring reception thresholds for sentences (RTS in dB), using HINT sentences presented at 0° with R-SpaceTM restaurant noise held constant at 65dBA and presented via eight loudspeakers set 45° apart. In addition, the APHAB was administered to assess subjective impressions of the experimental aid. Results revealed that significant differences in RTS (in dB) were present between directional and omnidirectional performance, as well as directional and unaided performance. Aided omnidirectional performance, however, was not significantly different from unaided performance. These findings suggest for the hearing aids and experimental condition used in this study, a patient would require directional microphones in order to perform significantly better than unaided or aided with omnidirectional microphones, and that performance with an omnidirectional microphone would not be significantly better than unaided. Finally, the APHAB-aided scores were significantly better than unaided scores for the EC, BN, RV, and AV subscales indicating the subjects, on average, perceived the experimental aid to provide significantly better performance than unaided, and that aided performance was more aversive than unaided.

Wireless CROS Versus Transcranial CROS for Unilateral Hearing Loss

Eight subjects with unilateral hearing loss were fitted with wireless CROS and transcranial BTE CROS hearing aids. Results revealed that two subjects preferred the BTE transcranial CROS; four subje...

Intratester Test-Retest Reliability of Insertion Gain Measures

Intratester test-retest reliability of insertion gain was determined on 28 subjects using the Frye 6500 real-ear analyzer. Results revealed mean differences of less than 1 dB for repeat measurements at six test frequencies between 250 and 4000 Hz. Also, over 80% of the repeat measures were within +/- 3 dB of the first measure. The results of this study are compared with previous studies of intratester reliability of insertion gain measures.

Effectiveness of the Directional Microphone in the Baha® Divino™

BACKGROUND Patients with unilateral sensorineural hearing loss (USNHL) experience great difficulty listening to speech in noisy environments. A directional microphone (DM) could potentially improve speech recognition in this difficult listening environment. It is well known that DMs in behind-the-ear (BTE) and custom hearing aids can provide a greater signal-to-noise ratio (SNR) in comparison to an omnidirectional microphone (OM) to improve speech recognition in noise for persons with hearing impairment. Studies examining the DM in bone anchored auditory osseointegrated implants (Baha), however, have been mixed, with little to no benefit reported for the DM compared to an OM. PURPOSE The primary purpose of this study was to determine if there are statistically significant differences in the mean reception threshold for sentences (RTS in dB) in noise between the OM and DM in the Baha® Divino™. The RTS of these two microphone modes was measured utilizing two loudspeaker arrays (speech from 0° and noise from 180° or a diffuse eight-loudspeaker array) and with the better ear open or closed with an earmold impression and noise attenuating earmuff. Subjective benefit was assessed using the Abbreviated Profile of Hearing Aid Benefit (APHAB) to compare unaided and aided (Divino OM and DM combined) problem scores. RESEARCH DESIGN A repeated measures design was utilized, with each subject counterbalanced to each of the eight treatment levels for three independent variables: (1) microphone (OM and DM), (2) loudspeaker array (180° and diffuse), and (3) better ear (open and closed). STUDY SAMPLE Sixteen subjects with USNHL currently utilizing the Baha were recruited from Washington Universitys Center for Advanced Medicine and the surrounding area. DATA COLLECTION AND ANALYSIS Subjects were tested at the initial visit if they entered the study wearing the Divino or after at least four weeks of acclimatization to a loaner Divino. The RTS was determined utilizing Hearing in Noise Test (HINT) sentences in the R-Space™ system, and subjective benefit was determined utilizing the APHAB. A three-way repeated measures analysis of variance (ANOVA) and a paired samples t-test were utilized to analyze results of the HINT and APHAB, respectively. RESULTS Results revealed statistically significant differences within microphone (p < 0.001; directional advantage of 3.2 dB), loudspeaker array (p = 0.046; 180° advantage of 1.1 dB), and better ear conditions (p < 0.001; open ear advantage of 4.9 dB). Results from the APHAB revealed statistically and clinically significant benefit for the Divino relative to unaided on the subscales of Ease of Communication (EC) (p = 0.037), Background Noise (BN) (p < 0.001), and Reverberation (RV) (p = 0.005). CONCLUSIONS The Divinos DM provides a statistically significant improvement in speech recognition in noise compared to the OM for subjects with USNHL. Therefore, it is recommended that audiologists consider selecting a Baha with a DM to provide improved speech recognition performance in noisy listening environments.

Fitting options for adults with unilateral hearing loss

You sound like many professionals who believe that patients with unilateral hearing loss (UHL) don’t have major problems. The notion is that such people only need to be counseled to make sure their good ear is facing the wanted signal. It’s true that preferential seating can resolve some of these patients’ listening problems. However, being required to “scan” the environment constantly is difficult and tiring and these patients cannot always do this successfully. In addition, patients with UHL still have problems with: (1) localizing, (2) understanding speech arriving at the poorer ear, and (3) understanding speech in background noise, especially when the noise arrives at the better ear. For these patients, audiologists often recommend Contralateral Routing Of the Signal (CROS) amplification to the better ear. Recently, several new fitting options have become available for these patients.

Study measures impact of hearing aids plus FM on the quality of life in older adults

Presbycusis, or hearing loss associated with the aging process, is one of the most common chronic conditions afflicting the older adult population today. Almost half the population over 65 years exhibits some degree of hearing impairment.1-4 The major consequence of presbycusis is difficulty in communication, particularly in noisy and/or reverberant listening situations.5-7 Due to these communicative difficulties, reduced psychosocial functioning in this population has often been reported. In particular, declines in social interaction, intimate relations, self-concept, psychological status, and cognition have been noted.3,8-13 For example, Mulrow et al. evaluated the effect of hearing loss on quality of life in older men.3 Results revealed that the presence of hearing loss was highly associated with decline in emotional, social, and communication performance. Additionally, Sherer and Frisina evaluated the effects of minimal hearing impairment on quality of life.14 This investigation found that the subjects with hearing impairment reported greater communicative, social, and emotional handicap, as well as lower selfesteem and social satisfaction, than did individuals without measurable hearing loss. In addition to psychosocial effects, hearing loss has also been shown to compromise physical health status.8,15,16 Carabellese et al. reported that elderly persons with hearing deficit were at an increased risk for difficulties in accomplishing activities of daily living.8 Additionally, Bess et al. reported that presbycusis was associated with an increased incidence of health-related diseases, such as hypertension, ischemic heart disease, arrhythmias, and osteoarthritis.15 Moreover, this study indicated that the greater the hearing impairment, the greater the prevalence of these healthrelated dysfunctions. One possible solution to the aforementioned declines in psychosocial and functional health status is the use of amplification. Past studies have revealed that persons using amplification reported fewer depressive feelings, richer social relationships, and higher quality of life than those who did not.17,18 For example, Mulrow et al. evaluated elderly veterans with hearing impairment after the provision of hearing aids.18 They noted improvements in social, emotional, and communication areas. Crandell found that the use of amplification could also positively affect functional health status.19 In his study, 20 elderly individuals with mild to severe sensorineural hearing loss were evaluated via the Sickness Impact Profile (SIP),20 the Short Form-36 Health Survey (SF-36),21 and the Abbreviated Profile of Hearing Aid Benefit (APHAB).22 The forms were administered before the fitting of hearing aids and at 3 and 6 months afterward. APHAB scores indicated improved communicative function with the use of amplification. After 3 months of hearing aid use, statistically significant improvements in physical and psychosocial functioning, as measured by the SIP, were noted. This positive trend remained stable for 6 months after the initial fitting. Although not statistically significant, slight improvements in the SF-36 were also noted. Although prior studies have evaluated the psychosocial and functional health benefits of hearing aids, none have examined the benefits of frequency modulation (FM) systems. When a personal FM system is employed, the speaker’s voice is picked up via an FM wireless microphone located near his/her mouth where the detrimental effects of reverberation and noise are minimal. The acoustic signal is then converted to an electrical waveform and transmitted via an FM signal to a receiver tuned to the same frequency. The electrical signal is then amplified, converted back to an acoustical waveform, and conveyed to the listener. We are currently conducting research on the possible psychosocial and physical health benefits of hearing aids that incorporate recent FM technologies.

Cost as a Barrier for Hearing Aid Adoption

Grundfast and Liu1 recently provided otolaryngologists with an overview of the hearing aid market. While their viewpoint addressed valid points, some points did not accurately reflect the hearing aid market. In this Viewpoint, we hope to provide otolaryngologists with a more accurate representation of hearing aids as part of audiologic service delivery. Grundfast and Liu1 correctly state that the hearing aid adoption rate is approximately 33%. The authors attribute this “poor” adoption rate primarily to cost, which can exceed