Development of the Three-Clinic Hearing Aid Selection Profile (HASP).

The Three-Clinic Hearing Aid Selection Profile (HASP) was developed to assess a patient's beliefs about a number of basic considerations felt to be critical to the hearing aid selection (HAS) process. These characteristics are felt to be key to the acceptance of amplification and include motivation, expectations, cost of goods and services, appearance (cosmesis), attitudes about technology, physical function/limitations, communication needs, and lifestyle. The results of the first investigation suggest that we have been successful in developing a 40-item metric with adequate internal consistency reliability that assesses the aforementioned characteristics. Second, results of the administration of this tool to a large group of individuals indicated that (1) age impacted scores on the Technology, Physical Function, and Communicative Needs subscales; (2) gender impacted scores on the Motivation, Expectation, Technology, Communicative Needs, and Appearance subscales; (3) previous hearing aid use affected scores on the Motivation subscale; (4) level of education impacted scores on the Physical Function and Lifestyle subscales; and (5) self-perceived hearing handicap had an effect on Motivation and Communicative Needs subscale scores. Percentile data collected from this subject sample are presented as a benchmark against which to evaluate responses from individual patients. Case studies are presented to illustrate the potential clinical utility of this device.

Open trial of methotrexate as treatment for autoimmune hearing loss.

OBJECTIVE: To assess the efficacy of low-dose methotrexate (MTX) administered for the treatment of autoimmune hearing loss. METHODS: This was a prospective, 12-month, open-label study of 17 patients with refractory autoimmune hearing loss. All patients had ongoing episodic worsening of hearing in one or both ears prior to enrollment despite traditional medical therapy. The MTX dose was 7.5-25 mg/week. Hearing loss and vertigo were evaluated at baseline and at completion of the study. Hearing improvement was defined as an improvement in pure tone threshold (PT) average of >10 dB or an increase in speech discrimination (SD) of >15%; worsening was defined as a decrease of >10 dB in PT or a decrease of >15% in SD in at least one ear. RESULTS: MTX was well tolerated. Among patients with Meniere's disease, 5 of 9 had improvement or resolution of vertigo. Equilibrium improved in all 3 patients with Cogan's syndrome and improved in 2 out of 3 patients with idiopathic hearing loss and this symptom. According to the parameters defined above, hearing improved in 11 patients (65%), was unchanged in 4 patients (23%), and worsened in 2 patients (12%). CONCLUSION: Long-term low-dose MTX therapy may be a useful therapy for at least some patients who have hearing loss with a presumptively autoimmune-mediated component that is refractory to traditional therapies.

Use of methotrexate for autoimmune hearing loss.

To assess the efficacy of low-dose methotrexate (MTX) given long-term for the treatment of autoimmune hearing loss, we performed a prospective open-label study of 11 patients with treatment-refractory autoimmune hearing loss. All patients had ongoing episodic worsening of hearing in 1 or both ears before enrollment despite traditional medical therapy. The MTX dose was 7.5 to 17.5 mg/wk. Hearing loss and vertigo were evaluated at baseline and at completion of the study. Hearing improvement was defined as an improvement in the pure tone threshold (PT) average of >10 dB or an increase in speech discrimination (SD) of >15%, whereas worsening was defined as a worsening of >10 dB in PT or a decrease of >15% in SD in at least 1 ear. The MTX was well tolerated. Among the 6 patients with Meniere's disease. 4 had improvement or resolution of vertigo, while 2 had no improvement. Disequilibrium improved in all 3 patients with Cogan's syndrome. According to the parameters defined above, hearing improved in 9 patients (82%), was unchanged in 1 patient (9%), and worsened in 1 patient (9%). Long-term low-dose MTX therapy may be a useful therapy for some patients who have hearing loss with a presumptively autoimmune-mediated component that is refractory to traditional therapies.

Audiometric findings in patients with acoustic neuroma.

OBJECTIVE: Hearing loss remains the most common symptom associated with acoustic neuroma. This study documents the audiometric findings from 721 acoustic neuroma procedures. STUDY DESIGN: This was a retrospective study. The preoperative audiometric data were compiled and were analyzed by patient age, gender, tumor size, time of surgery, and neurofibromatosis Type 2 (NF 2). Postoperative audiometric data were arranged and compiled in the same way. The hearing classification proposed by the AAO-HNS was applied to all preoperative and postoperative cases. SETTING: Tertiary referral center. PATIENTS: Surgically confirmed acoustic neuroma patients who had not previously received surgical or radiosurgical therapy. Patients underwent surgery by the retrosigmoid approach. INTERVENTION: Surgical removal of an acoustic neuroma. MAIN OUTCOME RESULT: Provision of pure tone and speech data from a group of acoustic neuroma patients, including application of the recently introduced and accepted AAO-HNS hearing classification system. RESULTS: Preoperative audiometric data were obtained from 694 of 721 patients (96%), of whom 619 had measurable hearing. Postoperative audiometry was performed on 606 patients; 152 had usable data. The combined preoperative audiometric data revealed a high frequency sensorineural hearing loss. Word recognition was servicable. The postoperative pure tones and word recognition scores were worse than preoperative scores. Age, gender, tumor size, and time of surgery had some impact on the preoperative hearing and the postoperative result; NF 2 did not. CONCLUSIONS: The study confirms that hearing alteration is almost universal in acoustic neuroma patients. Hearing preservation is possible in a significant number of cases; however, the postoperative auditory function tends to be worse.

Hearing loss and phacoemulsification.

PURPOSE: To determine the acoustic spectra of currently used phacoemulsification units and to contrast phacoemulsification-generated acoustic spectra with representative audiograms of common types of sensorineural hearing loss. SETTING: Mayo Clinic, Rochester, Minnesota, USA. METHODS: The acoustic spectra of 3 phacoemulsification systems (Alcon Series 20,000 Legacy, Storz Millennium, and AMO Diplomax) were recorded in an acoustically soundproofed room using a Roland VS-880 Digital Studio Workstation and analyzed with a Hewlett-Packard 35660A Dynamic Signal Analyzer. RESULTS: Phacoemulsification handpiece-generated harmonic overtones produced during ultrasound mode (6.0, 12.0, and 18.8 kHz for the 20,000 Legacy and Diplomax; 7.0 and 14.2 kHz for the Millennium) were outside the range of minimal decibel loss in individuals with hearing loss. Supplemental, low-frequency, console-generated tones produced during ultrasound mode (0.4 to 2.0 kHz for the Diplomax; 0. 1 to 1.5 kHz for the Millennium) were within the range of minimal decibel loss in individuals with hearing loss. CONCLUSION: Phacoemulsification systems with console-generated, low-frequency tones were audible to ophthalmologists with common types of sensorineural hearing loss.

Comparing the performance of the Widex SENSO digital hearing aid with analog hearing aids.

Differences in performance were evaluated between the Widex SENSO and several analog hearing aids currently worn by 50 hearing-impaired subjects. Subjects were initially fit with the SENSO using the manufacturer's recommended procedure. After wearing the hearing aids for 1 week, the adjustable parameters were fine-tuned based on subjective comments. Differences in performance between the SENSO and the subjects' current hearing aids were assessed using the Speech Perception in Noise administered at overall levels of 50, 65, and 80 dB SPL; the Hearing in Noise Test in which the background noise was presented at 50, 65, and 80 dBA; the Abbreviated Profile of Hearing Aid Benefit; and two questionnaires relating to overall preference between the SENSO and the subjects' current hearing aids.

Effect of temperature elevation on rabbit cochlear function as measured by distortion-product otoacoustic emissions.

Low-intensity laser stapedotomy has been shown to produce temperature elevations of 3 degrees to 4 degrees C within the cochlea. This study investigates the effect of temperature elevations in this range on cochlear outer hair cell function by use of distortion-product otoacoustic emissions in rabbits. Using esophageal temperature monitoring, we compared 2f1-f2 distortion-product otoacoustic emissions over a range of frequencies (1806 to 8691 Hz) at rabbit normothermia, normothermia plus 3 degrees C, and normothermia after passive cooling. Cochlear temperature was found to exceed changes in esophageal temperature by as much as 1.2 degrees C. We found that a maximum of 3 degrees C elevation in esophageal temperature did not permanently impair outer hair cell function in the rabbit cochlea. Results of this study suggest that moderate changes in cochlear temperature, such as those produced by low-intensity CO2 and holmium-yttrium aluminum garnet lasers, may not produce irreversible thermal damage to the cochlear outer hair cells.

Recognition of speech in noise with hearing aids using dual microphones.

Fifty subjects with mild to moderately severe sensorineural hearing loss and prior experience with amplification were evaluated at two sites (25 subjects at each site). Speech recognition in noise scores were measured using the Hearing in Noise Test (HINT) for each subject while wearing binaural behind-the-ear hearing aids allowing switching between two fitting algorithms ("basic" and "party") and two microphone conditions (single microphone omnidirectional and dual-microphone directional). Results revealed an average improvement in signal-to-noise ration (SNR) of 7.4 to 8.5 dB at the two sites for the directional conditions in comparison to the omnidirectional conditions. No significant improvement in SNR was measured between the two fitting algorithms. In addition, the Profile of Hearing Aid Benefit (PHAB) (Site I) and the Abbreviated Profile of Hearing Aid Benefit (APHAB) (Site II) were administered. Results revealed that the benefit scores for background noise and reduced cues (Site I) and background noise and aversiveness of sounds (Site II) were significantly higher than those reported in the established norms. Finally, 76 percent of the subjects of Site I reported that the experimental hearing aids provided "significantly better" or "better" performance than their current hearing aids.

Hearing loss as occupational hazard.

Is the technology any better today than it has been? Without question, there have been improvements in the past five years that enable hearing aids to better fit noise-induced hearing losses. The bottom line, however, is that hearing aids are still a prosthesis, not a solution to the problem of hearing loss. The final decision of whether to purchase a hearing aid or not is dependent upon many factors that should be discussed with your health care professional. Hearing aids have improved a lot in recent years, but their function still boils down to two important tasks: selectively amplifying sounds not heard by the individual, and preventing loud sounds from reaching uncomfortable levels.

Noise reduction with FM systems in FM/EM mode.

Commercially available noise reduction hearing aids have failed to deliver improved speech recognition in noise over properly fit conventional devices under typical listening conditions (Fabry & Van Tasell, 1990; Gabrielsson, Schenkman, & Hagerman, 1988; Tyler & Kuk, 1989; Van Tasell, Larsen, & Fabry, 1988). The primary factor related to this finding is that speech and noise are mixed at the input of a single microphone; spectral changes are applied equally to both speech and noise, and the signal-to-noise ratio remains unchanged from unprocessed conditions. The purpose of this study was to evaluate a prototype frequency-modulated (FM) auditory trainer that allowed use of a remote FM microphone and/or an ear level environmental microphone (EM). For each of five subjects with moderate to severe sensorineural hearing loss, the frequency response of the EM was configured either to match that of the FM response, or to provide a high-pass filter characteristic similar to a noise reduction hearing aid. Speech recognition threshold (SRT) testing noise was measured for five test conditions: 1) FM only; 2) EM only with high-pass filter response (EM-HP); 3) EM only with "standard" response (EM-S) matched to FM; 4) FM/EM-HP combined mode; and 5) FM/EM-S mode. Results averaged across subjects indicated that SRTs for the FM only condition were 9 to 10 dB better than those for either EM only condition; data from the combined FM/EM-HP mode averaged 4 dB better than for FM/EM-S conditions.

Clinical and communication access through amplification for a medical student with severe hearing loss: case report.

This case report focuses on the communication difficulties of a 21-year-old medical student with severe-to-profound sensorineural hearing loss. The greatest difficulties reported by the patient were for stethoscope use and slide presentations in darkened rooms. Successful audiologic management was accomplished for this patient via use of a behind-the-ear (BTE) FM system for classroom use and a "homemade" amplified stethoscope that enabled him to hear diagnostic heart sounds for clinical use. The amplified stethoscope provided greater low-frequency gain for this patient than was available through other commercial units.

Do adaptive frequency response (AFR) hearing aids reduce 'upward spread' of masking?

Speech recognition scores in noise are improved for some subjects who wear hearing aids that reduce low-frequency noise with an adjustable high-pass filter circuit. To evaluate whether these improvements were related to a reduction in upward spread of masking, pure-tone masking patterns for a low-frequency band-pass noise were measured in normal and hearing-impaired subjects. The filter skirt of the noise masker was very steep, with attenuation above the 1000 Hz cutoff greater than 120 dB per octave. Masking patterns for the same noise were also obtained in the presence of a high-pass filter that simulated the effects of an adaptive frequency response (AFR) hearing aid. Differences in the masking patterns were considered a measure of upward spread of masking. On average, subjects with high-frequency hearing loss demonstrated greater amounts of upward spread of masking than did normal-hearing listeners. Further, monosyllabic speech recognition in noise testing indicated improvements in performance of the hearing-impaired subjects related to the decrease of upward spread of masking in the high-pass filtering conditions.

Detection and recognition of stop consonants by normal-hearing and hearing-impaired listeners.

This study examined the possibility that hearing-impaired listeners, in addition to displaying poorer-than-normal recognition of speech presented in background noise, require a larger signal-to-noise ratio for the detection of the speech sounds. Psychometric functions for the detection and recognition of stop consonants were obtained from both normal-hearing and hearing-impaired listeners. Expressing the speech levels in terms of their short-term spectra, the detection of consonants for both subject groups occurred at the same signal-to-noise ratio. In contrast, the hearing-impaired listeners displayed poorer recognition performance than the normal-hearing listeners. These results imply that the higher signal-to-noise ratios required for a given level of recognition by some subjects with hearing loss are not due in part to a deficit in detection of the signals in the masking noise, but rather are due exclusively to a deficit in recognition.

Improving the frequency specificity of the auditory brain stem response.

Several investigators have suggested that the use of tonal stimuli shaped with nonlinear windowing functions can improve the frequency specificity of the auditory brain stem response (ABR). This study investigated the effects of different windowing functions on the ABR for 30 normal-hearing adults and 30 adults with high-frequency hearing loss. These hearing-impaired patients often produce an abnormal click-evoked ABR because of the influence of the high-frequency loss. Each subject was evaluated using a click stimulus and a 500 Hz tone burst gated with one linear and four nonlinear windowing functions. There were no significant differences in wave V latency between the groups for any of the five windowed tone burst conditions. These results suggest that any of the windowing functions used would be effective for 500 Hz tonal ABRs with this population of hearing-impaired adults.

Effects of different frequency response strategies upon recognition and preference for audible speech stimuli.

The purpose of this study was to examine whether the amount of low- versus high-frequency amplification should change as a function of input level, as is done in some recently developed hearing aids. Adults with high-frequency sensorineural hearing loss served as subjects. Both identification performance and preference judgments for audible CV syllables were assessed as a function of input level for three different signal processing conditions both in quiet and in noise. The first signal processing condition was a conventional high-pass frequency response that did not change its transfer function as the input level increased; the second condition was similar to a typical adaptive frequency response (AFR) hearing aid: a high-pass frequency response that became increasingly high-pass as the input level increased; the third condition was similar to the K-Amp hearing aid recommended by Killion (1988): a high-pass frequency response that became more broadband as the input level increased. Results indicated no significant differences among the three different processing conditions for syllable recognition and a strong listener preference for the syllables presented via the conventional amplification scheme.

Comparison of three hearing aid fittings using the Speech Intelligibility Rating (SIR) Test.

This study compared the effects of three different hearing aids on subjective ratings of speech intelligibility. Insertion gain measurements on KEMAR indicated that the hearing aid fittings differed primarily in midfrequency gain. The test passages of the Speech Intelligibility Rating Test (SIR) were recorded onto tape through each hearing aid. The processed passages were presented monaurally to 13 subjects with hearing loss limited to frequencies above 2000 Hz. They rated five passages through each frequency responses (FR) in a randomized order. Each subject was retested within 2 or 3 days to assess test-retest reliability. Results indicated that the FR with the most midfrequency amplification did not differ significantly from the aid with the least amount of midfrequency gain. However, the FR with intermediate midfrequency gain received significantly lower ratings than did FR with most gain. Examination of the data from individual subjects indicated that the SIR results did not show differences among the FRs for the majority of subjects.

Evaluation of an articulation-index based model for predicting the effects of adaptive frequency response hearing aids.

The Articulation Index (AI) was used to evaluate an "adaptive frequency response" (AFR) hearing aid with amplification characteristics that automatically change to become more high-pass with increasing levels of background noise. Speech intelligibility ratings of connected discourse by normal-hearing subjects were predicted well by an empirically derived AI transfer function. That transfer function was used to predict aided speech intelligibility ratings by 12 hearing-impaired subjects wearing a master hearing aid with the Argosy Manhattan Circuit enabled (AFR-on) or disabled (AFR-off). For all subjects, the AI predicted no improvements in speech intelligibility for the AFR-on versus AFR-off condition, and no significant improvements in rated intelligibility were observed. The ability of the AI to predict aided speech intelligibility varied across subjects. However, ratings from every hearing-impaired subject were related monotonically to AI. Therefore, AI calculations may be used to predict relative--but not absolute--levels of speech intelligibility produced under different amplification conditions.