Publication Abstracts - 2003

Fausti S.A., Helt W.J., Phillips D.S., Gordon J.S., Bratt G.W., Suguira K.M., Noffsinger D. Early detection of ototoxicity using 1/6th octave steps. Accepted, Journal of the American Academy of Audiology, 2003.

VA RR&D National Center for Rehabilitative Auditory Research, Portland VA Medical Center, Portland, Oregon 97239, USA. Stephen.fausti@va.gov

The National Center for Rehabilitative Auditory Research has developed a protocol to provide early identification of ototoxicity for patients receiving ototoxic medications. The initial work involved patients with relatively good high-frequency hearing and resulted in the use of an individualized, sensitive frequency range separated by 1/6th-octave intervals. This protocol tested pure-tone frequencies at 1/6th-octave steps above 9 kHz, but only conventional audiometric frequencies were tested below 9 kHz. More recently, the testing protocol was expanded to include 1/6th-octave testing below 9 kHz. The primary question of interest was to determine whether adding 1/6th-octave test frequencies below 9 kHz would increase the ototoxicity detection rate for patients with poorer hearing. Results indicated 76 of the 210 (36.2%) ears that demonstrated initial ototoxic hearing change would have been missed or detected later if only conventional frequency testing was conducted.Therefore, for individuals with poorer hearing, expanding the use of the 1/6th-octave test protocol provides earlier identification of ototoxicity.

Fausti, S.A., Flick, C.L., Bobal, A.M., Ellingson, R.M., Henry, J.A., and Mitchell, C.R. Comparison of ABR stimuli for the early detection of ototoxicity: Conventional clicks compared with high frequency clicks and single frequency tonebursts. Accepted, Journal of the American Academy of Audiology, 2003.

National Center for Rehabilitative Auditory Research, 3710 SW US Veterans Hospital Road (R&D-NCRAR), Portland, Oregon 97207, USA. stephen.fausti@va.gov

Effective objective testing methodology is needed for early detection of the effects of ototoxicity on hearing in patients. The requirements for such testing include responses that are: 1) reliable across test sessions; 2) sensitive to ototoxic change ( > 8 kHz), and 3) recordable in a time-efficient manner. Auditory brainstem responses (ABR) appear well suited to this task however, conventional clicks stimulate primarily mid-frequencies (1-4 kHz) and high frequency tonebursts require too much time. We hypothesized that delivery of a band of high frequencies (a high frequency "click"), would elicit reliable and useful ABRs. In the current study, flat and sloped HF (high frequency) clicks with a bandwidth of 8-14 kHz were used. The purpose was to compare brainstem responses elicited by tonebursts, two HF clicks and conventional clicks. The results show that the reliability of responses to the HF clicks were comparable to the tonebursts and further, both HF clicks produced responses slightly larger than tonebursts.

Henry, J.A., Flick, C.L., Gilbert, A.M., Ellingson, R.M., and Fausti, S.A. (2003). Reliability of computer-automated hearing thresholds in cochlear-impaired listeners using ER-4B Canal Phone TM earphones. Journal of Rehabilitation Research and Development, 40 (3): 253-264

Department of Veterans Affairs Rehabilitation Research and Development, National Center for Rehabilitative Auditory Research, VA Medical Center, Portland, OR 97207, USA. james.henry@va.gov

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.

Henry J.A., Jastreboff M.M., Jastreboff P.J., Schechter M.A., Fausti S.A. (2003) Guide to conducting tinnitus retraining therapy initial and follow-up interviews. Journal of Rehabilitation Research and Development, 40(2): 159-179.

Department of Veterans Affairs (VA) Rehabilitation Research and Development, VA Medical Center, Portland, OR 97207, USA. james.henry@va.gov

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.

Hodoshima, N., Arai T., Inoue T., Kinoshita K., Kusumoto A. (2003). "Improving intelligibility of speech by steady-state suppression as pre-processing in small to medium sized halls". To be published, European Conference on Speech communication and Technology (Eurospeech).

Konrad-Martin, D., Keefe, D.H. (2003). Time-frequency analyses of transient-evoked stimulus-frequency and distortion-product otoacoustic emissions: Testing cochlear model predictions. J. Acoust. Soc. Am. 114, 2021-2048.

VA RR&D National Center For Rehabilitative Auditory Research, Portland VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, USA. dawn.martin@va.gov

Time-frequency representations (TFRs) of otoacoustic emissions (OAEs) provide information simultaneously in time and frequency that may be obscured in waveform or spectral analyses. TFRs were applied to transient-evoked stimulus-frequency (SF) and distortion-product (DP) OAEs to test cochlear model predictions. SFOAEs and DPOAEs were elicited in 18 normal-hearing subjects using gated tones and tone pips. Synchronous spontaneous (SS) OAEs were measured to assess their contributions to SFOAEs and DPOAEs. A common form of TFR of measured OAEs was a collection of frequency-specific components often aligned with SSOAE sites, with each component characterized by one or more brief segments or a single long-duration segment. The spectral envelope of evoked OAEs differed from that of the evoking stimulus. Strong emission regions or cochlear "hot spots" were detected, and sometimes accounted for OAE energy observed outside the stimulus bandwidth. Contributions of hot spots and multiple internal reflections to the OAE, and differences between measured and predicted OAE spectra, increased as stimulus level decreased, consistent with level-dependent changes in the estimated cochlear reflectance. Suppression and frequency-pulling effects between components were observed. A recursive formulation was described for the linear coherent reflection emission theory [Zweig and Shera, J. Acoust. Soc. Am. 98, 2018-2047 (1995)] that is well suited for time-domain calculations.

Kusumoto, A., Arai T., Kinoshita K., Hodoshima, N. Modulation Enhancement of Speech by Preprocessing for Improving Intelligibility in Reverberant Environment. Submitted, Speech Communication, 2003

Lewis, M.S., Crandell, C., & Kreisman, N. (Under review). Frequency modulation (FM) technology and speech perception in noise: Effect of microphone and fitting configuration. Ear & Hearing, 2003

Lewis, M.S., Crandell, C., Valente, M., & Enrietto, J. (Under review). Speech perception in noise: Directional microphones versus frequency modulation (FM) systems. Journal of the American Academy of Audiology, 2003.

Lewis, M.S., Crandell, C., Valente, M., Enrietto, J., Kreisman, N., Kreisman, B., & Bancroft, L. (2003). Study measures impact of hearing aid plus FM on the quality of life in older adults. The Hearing Journal, 56(2), 30-33.

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. 

The major consequence of presbycusis is difficulty in communication, particularly in noisy and/or reverberant listening situations.  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.

For example, Mulrow ret al. evaluated the effect of hearing loss on quality of life in older men.  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.  This investigation found that the subjects with hearing impairment reported greater communicative, social and emotional handicap, as well as lower self-esteem 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.  Carabellese et al. reported that elderly persons with hearing deficit were at an increased risk for difficulties in accomplishing activities of daily living. Additionally, Bess et al. reported that presbycusis was associated with an increased incidence of health-related diseases, such as hypertension, ischemic heart disease, arrhythmias, as osteoarthritis.  Moreover, this study indicated tha thte greater the hearing impairment, the greater the prevalence of these health related 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.

For example, Marlow et al. evaluated elderly veterans with hearing impairment after the provision of hearing aids.  They noted improvements in social, emotional, and communication areas.

Crandell found that the use of amplification could also positively affect functional health status.  In his study, 20 elderly individuals with mild to severe sensorineural hearing loss were evaluated via the Sickness Impact Profile (SIP), the Short Form-36 Health Survey (SF-36) and the Abbreviated Profile of Hearing Aid Benefit (APHAB). 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 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 them amplified, converted back to an acoustical waveform, and conveyed to the listener.

We are currently conducting research on eh possible psychosocial and physical health benefits of hearing aids that incorporate recent FM technologies.

Mitchell, C.R., Ellingson, R.M., Henry, J.A., and Fausti, S.A. The utilization of auditory brainstem responses for the early detection of ototoxicity from aminoglycosides or chemotherapeutic drugs. In press. Journal of the American Academy of Audiology, 2003.

Salinsky, M.C., Oken, B.S., Storzbach, D., and Dodrill, C.B. Assessment of CNS effects of antiepileptic drugs using quantitative EEG measures. Epilepsia 44:1042-1050.

Oregon Health and Science University Epilepsy Center, Portland, Or 97239, USA. Salinsky@OHSU.edu

PURPOSE: Antiepileptic drugs (AEDs) can be associated with adverse neurologic effects including cognitive dysfunction. Objective methods for recognizing AED effects on the brain could be valuable for long-term management. We compared quantitative EEG measures and cognitive tests in a group of patients beginning or ending AED therapy. METHODS: Subjects included 20 patients beginning AED therapy (AEDon), 12 patients stopping AED therapy (AEDoff), 33 patient controls receiving stable AED therapy (AEDco), and 73 healthy controls (Nco). All subjects underwent structured EEG recording and a cognitive test battery before change in AED dose and again 12-16 weeks later, >or=4 weeks after the last dose change. Four occipital EEG measures (peak frequency, median frequency, relative theta and delta power) were analyzed. Cognitive test changes were scored by using test-retest regression equations based on the Nco subjects. Wilcoxon tests were used for two-group comparisons. RESULTS: AEDons had a significant decrease, and AEDoffs, a significant increase in the peak frequency of the EEG rhythm, as compared with controls. Results for median frequency and theta power were similar. Change in the EEG peak frequency correlated with an aggregate cognitive change measure (r2= 0.71; p < 0.001), individual cognitive measures, and subjective complaints. Of the combined AEDon/AEDoff patients, 58% exceeded the 95% confidence interval for test-retest change in EEG peak frequency. CONCLUSIONS: Quantitative measures derived from the occipital EEG are sensitive to AEDs and correlate with AED-related cognitive effects and subjective complaints. Although this correlation does not indicate a direct relation, quantified EEG may be a practical measure of AED impact on the brain.

Saunders, GH & Morgan DE (2003) Impact of measuring threshold in dB HL versus dB SPL on hearing aid targets. International Journal of Audiology 6, 319-326.

National Center for Rehabilitative Auditory Research, Portland, OR 97207, USA. saunderg@ohsu.edu

Audiometric measurements are traditionally made in dB HL, which by definition are specified relative to the sound pressure level (SPL) in a coupler. Real-ear dB SPL is then estimated by applying an average ear transform to the coupler value. However, individual variation in ear canal acoustics and variations in transducer placement strongly influence the dB SPL of signals arriving at the eardrum. In this paper, data from 1814 ears are presented, showing that the distribution of eardrum dB SPL for a fixed signal level varies across ears and across frequency by as much as 40 dB. The impact of this variance upon hearing aid targets computed with the NAL-NL1 fitting algorithm is examined by comparing the targets obtained from using an average transform with those obtained when audiometric data in dB SPL are obtained by applying individually measured real-ear-to-coupler difference (RECD) values to dB HL thresholds. The impact can be considerable.