ABSTRACTS
24.2
Volume 24 Number 2 2002Summary of Highlights From the 7th International Tinnitus Seminar
Pam Gabriels
Director, Western Hearing Services, Perth, AustraliaThe highlights of the 7th International Tinnitus Seminar are presented in the following article. The papers that were of particular interest during the seminar were those presented by the keynote speakers and guest speakers.
A Conceptual Framework to Aid the Diagnosis and Treatment of Severe Tinnitus
Mary B. Meikle
Oregon Health and Science University, Portland, Oregon, USADiagnostic and treatment efforts for severe tinnitus are currently impeded by the lack of standardised methods for measuring the negative impacts of tinnitus upon the affected individuals. Such efforts could benefit from application of the World Health Organization (WHO) method for categorising the negative effects caused by chronic conditions. The WHO method starts by defining the relevant impairment (physical or mental), which leads to disability, and finally to handicap. Evaluating each patient’s status using the WHO categories of impairment, disability, and handicap can facilitate diagnostic and treatment efforts by clarifying relationships between specific problems and corresponding treatment needs. Systematic classification of patients’ tinnitus-related problems in this way can serve as a basis for comparing the content domains of different tinnitus questionnaires, and also can contribute unifying themes to aid in developing standardised methods for evaluating the severity of tinnitus. Such standardised measures are needed in order to provide a rational basis for stratifying patients for assignment to different treatment groups, and they will greatly facilitate meta-analyses and other types of comparison and evaluation of treatment results obtained at different centers.
Hyperacusis: Testing, Treatments and a Possible Mechanism
J.A.Vernon
Oregon Health and Science University, USAHyperacusis is a well known phenomenon consisting of a collapse of loudness tolerance. The following generalisations can be made: (1) Hyperacusis is not heightened hearing sensitivity (hearing thresholds are not better than normal); (2) hyperacusis is often accompanied by tinnitus; (3) the severity of hyperacusis is usually inversely proportional to the pitch of the offending noise; (4) perhaps most important, over-protection of the ears is a natural reaction of hyperacusic patients but it must be avoided as it progressively exacerbates hyperacusis. A testing procedure, which involves determining loudness discomfort levels at a number of frequencies, will be described and typical data will be presented. Successful treatment for hyperacusis involves two components: First, training patients to use sound level meters to distinguish between truly damaging sound levels versus those which simply sound too loud; and second, instructing them in the use of a desensitisation program which involves listening to pink noise for several hours daily, starting at a low sound level and progressively increasing it over a period of several months. A new type of protective hearing device will also be described which allows the wearer to avoid loud sounds while preventing over-protection of the ears. When using the device, known as the Star 2001, hyperacusis patients are able to go out and about without fear of encountering loud sounds.The theoretical basis for hyperacusis is not yet known but a potential neural mechanism will be discussed.
Decreased Sound Tolerance and Tinnitus Retraining Therapy (TRT)
Margaret M. Jastreboff and Pawel J. Jastreboff
Emory University School of Medicine, Atlanta, USAThe main objective of Tinnitus Retraining Therapy (TRT) is habituation of activation of the autonomic nervous system, evoked by signals present in the auditory pathways. Sound therapy aims at decreasing the strength of these signals. The same systems in the brain are involved in tinnitus and decreased sound tolerance, and the same basic neurophysiological mechanisms are utilised for decreasing the tinnitus-related neuronal activity and, in case of hyperacusis, abnormally enhanced activity induced by external sounds. The similarity of TRT treatment between tinnitus and misophonia is even closer, as in both situations the goal is to achieve extinction of functional connections between the auditory and the limbic and autonomic nervous systems. The increased gain within the auditory pathways that are presumably responsible for hyperacusis could enhance the tinnitus signal, thus it is possible to expect coexistence of tinnitus and hyperacusis, and the predisposition of hyperacusis patients to develop tinnitus. As such, for some patients tinnitus and hyperacusis may be considered the double manifestation of the same internal phenomenon.
Considerations When Evaluating a Tinnitus Patient for Compensation
Richard S. Tyler
The University of Iowa, USASeveral issues need to be considered when evaluating a tinnitus patient for compensation. First, it is necessary to determine that they actually have tinnitus. Questions that can be addressed include: “Is there a plausible cause?”, “Was the tinnitus reported before the patient considered a lawsuit?”, “Are the complaints consistent with other patients’ complaints of tinnitus?”, “Have others noted that the patient has difficulties attributed to tinnitus?”, “Has the patient faked a hearing loss or other ailment?”, “Are the tinnitus measurements reliable?”, and “Has the patient sought treatment?” Second, it is necessary to determine the severity. A new rating approach is proposed that considers the broad categories of concentration, emotional wellbeing, hearing and sleep. A preliminary version of a Tinnitus Impairment Questionnaire that addresses these four areas is presented. Third, the most probable cause of the tinnitus should be determined. One strategy is to consider all possible causes, and then decide on the most probable. If the case involves a noise induced hearing loss, it is necessary to distinguish between: noise exposure in the workplace over years; a single intense exposure; hunting or target shooting; recreational noise; noise exposure in military service; and noise exposure at previous work.
Wavelet Analysis for Audiologists
W. J. Wilson
Department of Speech Pathology and Audiology, School of Human and Community Development, University of the Witwatersrand, Johannesburg, South Africa, and Discipline of Audiology,
Faculty of Medical and Health Sciences, University of Auckland, Auckland, New ZealandWavelets and wavelet analysis represent a significant advance in our ability to record and analyse auditory evoked potentials (AEPs). Obtaining knowledge about this growing area can be difficult, however, as existing wavelet reviews are typically entrenched in mathematical theory. This paper provides the first practical wavelet review written for the clinical audiologist. Specifically, the paper will answer the question “what is a wavelet”, describe continuous and discrete wavelet analyses, describe four of the most promising applications of AEP wavelet analysis, review AEP wavelet research conducted to date, and comment on AEP wavelet applications for the future. It is hoped this review will give audiologists a better understanding of current AEP wavelet research, and prepare them for the clinical implications that will follow.
24.1
Volume 24 Number 1 2002
Conversion from the Body-worn Spectra to the Ear-level ESPrit22 in Children
Kerrie Plant, Lesley Whitford and Peter Seligman
Cochlear Limited and CRC for Cochlear Implant and Hearing Aid Innovation, AustraliaKatie Hill and Liz Winton
Royal Victorian Eye and Ear Hospital and CRC for Cochlear Implant and Hearing Aid Innovation, AustraliaJulie Decker
Children’s Cochlear Implant Centre and CRC for Cochlear Implant and Hearing Aid Innovation, AustraliaEmma Rushbrooke and Lia Lassig
Hear & Say Centre for Deaf Children and CRC for Cochlear Implant and Hearing Aid Innovation, AustraliaA multi-centre study was conducted involving 93 children, aged 5.7 to 18.0 years, who approached their cochlear implant centres for conversion from the body-worn Spectra to the ear-level ESPrit22 processor. Eighty-seven per cent of the children attending the centres could be fitted with the ESPrit22 without any program adjustment, 9% required some adjustment and 4% were unable to be fitted with the ESPrit22 because of high power requirements in the speech processor program. For subjects requiring significant adjustment to stimulation mode for ESPrit22 fitting an initial decrease in word recognition was observed, with progressive improvement over time. For those subjects where direct conversion from the Spectra to the ESPrit22 was possible (n = 60) mean monosyllabic open-set word recognition at initial fitting was equivalent between the two processors. However after using the ESPrit22 for a period of 4 weeks there was a significant improvement in performance from 46.5% with the Spectra to 54.4% with the ESPrit22. A similar pattern was observed for BKB sentence recognition in noise with a smaller group of 8 subjects. The majority of children reported immediate adjustment to the ESPrit22 and chose to use the ESPrit22 for most of the time in a range of listening environments.
The National Acoustic Laboratories’ (NAL) CDs of Speech and Noise for Hearing Aid Evaluation: Normative Data and Potential Applications
Gitte Keidser, Teresa Ching, Harvey Dillion, Katrina Agung, Christopher Brew, Scott Brewer, Michael Fisher, Levi Foster, Frances Grant, and Lydia Storey
National Acoustic Laboratories, Australia
This paper describes the speech and noise material on a new set of three CDs that is considered very suitable for hearing assessment and fine-tuning of hearing aids in audiological clinics. The material includes continuous discourses, various background noises, and three different speech test materials (BKB sentence test, four SPIN sentence lists, and Vowel-Consonant-Vowel (VCVs) nonsense syllables). All speech samples are recorded using native speakers of Australian English. Normative data in the form of the central part of performance-intensity functions are presented for the BKB sentences in babble-noise and for intelligibility rating of continuous discourse in nine background noises together with list-equivalence data for the BKB test. For each test, the critical difference that needs to be exceeded to obtain significantly different results is also presented. Applications for the material with respect to candidacy and hearing aid fine-tuning are discussed.
Case Study
A Case Study of Partial Agenesis of the Corpus Callosum: Audiological Implications
Leanne Skinner
Australian Hearing and The University of Queensland, Australia
Louise Hickson
The University of Queensland, AustraliaThis case study presents four and a half years of audiological observations, testing and aural habilitation of a female child with a partial agenesis of the corpus callosum (ACC). The ACC was diagnosed by MRI scan performed at 6 months of age to eliminate neurological causes for the developmental delay. This child was also born with a cleft palate and was diagnosed with Robinow Syndrome at 3 years and 3 months of age. The audiological results showed an improvement in hearing thresholds over the 4-year period. The child’s ophthalmologist also reported an improvement in visual skills over time. The most interesting aspect of the child’s hearing was the discrepancy between the monaural and the binaural results. That is, when assessed binaurally she often presented with a mild to moderate mixed loss and, when assessed monaurally, she showed a moderate to severe mixed loss for the right ear and a severe mixed loss for the left ear. Over time, the discrepancy between the monaural and binaural results changed. When assessed binaurally, the loss decreased to normal low frequency hearing sloping to a mild high frequency loss. When assessed monaurally, the most recent results showed a mild loss for the right ear and a moderate loss for the left ear. This discrepancy between binaural and monaural results was evident for both aided and unaided tests. For the most recent thresholds, the binaural results were consistent with the right monaural thresholds for the first time over the four and a half years. Parental reports of the child’s hearing were consistent with the binaural clinical results. This case indicates the need for audiologists to (1) carefully monitor the hearing of children with ACC, (2) obtain monaural and binaural hearing and aided thresholds results, and (3) compare these children’s functional abilities with the objective test results obtained. This case does question whether hearing aids are appropriate for children with ACC. If hearing aids are deemed to be appropriate, then hearing aids with compression characteristics should be considered.
Brief CommunicationsAudiology Outcomes in Infants Weighing Less than 1500 Grams at Birth
William Rush, Malcolm Battin, and Oriole Wilson
University of Auckland, National Women’s Hospital, and National Audiology Centre, New ZealandThe audiology outcomes for infants with a birth weight below 1500g were reviewed. Of 402 infants referred for audiology 319 (79%) attended. Two hundred and forty-six (77%) had sufficient hearing for the development of speech and language but 66 (21%) infants needed further testing and six infants (1.9%) had hearingimpairment.
Neonatal Transient Evoked Otoacoustic Emissions Screening: How Many Stimuli
Are Enough?Liza Cropper, Joseph Kei, Veronica Smyth
The University of Queensland, AustraliaMarian Maurer, June Young, David Tudehope
Mater Misericordiae Hospital, AustraliaBradley McPherson
The University of Hong Kong, Hong KongThe present study examined the effect of stimulus number on two pass criteria in neonatal transient evoked otoacoustic emission (TEOAE) screening. Participants were 25 normal, full-term neonates (mean age = 2.7 days, SD = 1.3), with normal peripheral auditory function in both ears. The Otodynamics ILO88 (Quickscreen) program was used and the TEOAE spectrum was analysed after the presentation of 10, 50, 100 and 260 stimuli. Two pass criteria were used: Criterion 1 — whole wave reproducibility (WWR) ³ 60%, and Criterion 2 — SNR ³ 3 dB for all three frequency bands centered at 2.4, 3.2 and 4.0 kHz. The results revealed that the number of stimuli used to achieve a “Pass” status depended on the pass criterion and the activity state of neonates. Although the use of an initial minimum stimulus number of 50 in neonatal TEOAE screening is justified, clinicians should continue testing if necessary until a set of predetermined stopping criteria are satisfied.