ABSTRACTS
Audiology
Audiology and the Educational Managemen of Children with Hearing Loss
Field W. Rickards
The University of Melbourne, AustraliaThis article is a shortened version of the Denis Byrne Memorial Oration to the Joint Conference of the Audiological Society of Australia and the New Zealand Audiological Society in Melbourne in March 2002. The article focuses on the important developments relevant to the management of hearing impaired children.
Evidence-Based Audiology and Clinical Excellence
Peter R. Thorne
University of Auckland, New ZealandThis article is based on the Kaye Coddington Memorial Lecture of the New Zealand Audiological Society presented at the Combined Meeting of the Australian and New Zealand Audiological Societies in Melbourne, March 2002. The annual lecture is given in memory of Kaye Coddington, a Clinical Audiologist who made a unique contribution to the audiology profession in New Zealand. The theme of the lecture, emphasising the importance of research in audiology, pays tribute to Kaye’s strong advocacy for clinical excellence and particularly the role that research plays in informing clinical practice.
Development and Evaluation of an Australian Version of the Pediatric Speech Intelligibility Test for Auditory Processing Disorder
Sharon Cameron, Rosalind Barker and Philip Newall
Macquarie University, AustraliaResearch has shown that the Pediatric Speech Intelligibility Test (PSI; Jerger & Jerger, 1984) is a sensitive tool for diagnosing auditory processing disorder (APD) in young children. The PSI is a speech test which utilises competing sentences presented dichotically and monotically at various message to competition ratios (MCRs). The purpose of the present study was to develop an Australian version of this test for use in local clinics. The Macquarie Pediatric Speech Intelligibility Test (MPSI) was recorded using Australian speakers, in order to control for linguistic differences which could affect performance on the test by Australian children. Normative data was collected from 51 normally hearing Australian children aged 7.0 to 8.11 years. The scores below which a child’s performance on the MPSI is considered indicative of APD were found to be comparable to those calculated for the original North American version of the test. No significant differences in performance between 7- and 8-year-olds were detected for either the monotic or dichotic conditions of the MPSI. The degree of right or left ear advantage on the dichotic task was very slight, regardless of handedness, making differentiating between the right and left ears when tabulating cut-off scores unnecessary. The preliminary results indicated that the MPSI will be a valuable tool in the identification of APD in the Australian school-aged population.
The Effect of Passing Time on Self-reported Satisfaction with Hearing Aid Amplification
Beth McLeod and Laurie Upfold
MAC Audiology Service, AustraliaThe self-report inventory Satisfaction with Amplification in Daily Life (SADL) has been found to give significantly different results if applied at 2 weeks and 12 months post-fitting. This finding did not indicate when satisfaction is stabilised. While a number of studies have suggested benefit from aid fitting is stabilised by 4–6 weeks post-fitting, benefit is only a small part of satisfaction as measured by the SADL. As a consequence, there can be no certainty that the time delay between fitting and stability of benefit is similar to that of satisfaction. An investigation was undertaken of post-fitting changes in satisfaction as measured by the SADL. A total of 383 pensioner clients were asked to complete the SADL at times ranging from 2 weeks to 12 months post-fitting. A net return of 281 SADLs was obtained, with different rates of return depending on time since fitting and method of administration. Factors related to non-return were also investigated. Satisfaction was assessed for eight different times post-fitting. The results indicated that different aspects of satisfaction stabilise to long-term levels at different times after fitting. It was concluded that application of the SADL before the third month post-fitting will overestimate long-term satisfaction in three of the five measures provided. As a consequence, decisions must be taken regarding when, and how, the measurement is to be performed.
Prediction of Non-Linear Amplification Using Different Loudness Scaling Tests
Gitte Keidser
National Acoustic Laboratories, AustraliaFrequency-specific loudness data are widely used in procedures for fitting non-linear hearing aids, with each procedure using different methods to obtain information about a person’s loudness perception. There has been some suggestion that due to differences in methodology different loudness tests result in different prediction of the non-linear amplification when applied according to the same fitting rationale. However, this has not been empirically verified. In this paper the inverse compression ratios prescribed based on a pure loudness normalisation technique and loudness data measured with two different categorical loudness scaling tests were compared for 20 test ears. The data showed that the two loudness tests produced significantly different prescriptions for non-linear amplification and that the discrepancy in prescription was non-linearly related to hearing threshold level with the greatest discrepancy found for cases with moderate loss. Differences in methodology used to obtain the loudness data are argued to be the most likely reason for the measured discrepancy in prescription. Up to 50% of a large variability in data across hearing threshold levels was explained by individual participant factors, suggesting that the interpretation of the two loudness tests varied across participants. The results imply that any fitting rationale based on frequency-specific loudness data is only valid for the test conditions in which the loudness data are obtained, and a hearing aid fitting based on frequency-specific loudness data should be verified.
Brief Communications
Cherbourg Revisited: Hearing Health Changes in an Aboriginal Community, 1972 to 2000
Ravi Sockalingam, Katye Hives and Joseph Kei
The University of Queensland, AustraliaBradley McPherson
University of Hong Kong, Hong KongThe aim of this study was to investigate current audiological outcomes of Cherbourg schoolchildren and compare these outcomes to those obtained in a 1972 study of hearing health in the same community. Seventy-eight primary school children of Cherbourg State School participated in the study. Their peripheral hearing and middle ear function were tested using pure-tone air conduction audiometry and tympanometry respectively. A significant improvement in the hearing status of this population was noted compared to that reported in 1972. The improvements in the hearing status of Indigenous schoolchildren at Cherbourg can be attributed to a number of factors, including increased awareness of both ear health and general health, as well as the introduction of hearing health care services, over the past three decades.
Behavioural and Electroacoustic Calibration of Air-conducted Click and Toneburst Auditory Brainstem Response Stimuli
Mridula Sharma and Suzanne C. Purdy
National Acoustic Laboratories, AustraliaLou Bonnici
Australian Hearing, AustraliaAlthough auditory brainstem response (ABR) audiometry is widely used to assess hearing sensitivity in infants and young children, normal calibration values vary across clinics. This study was undertaken to determine normal hearing thresholds for tonebursts and clicks with insert earphones. Techniques for performing electroacoustic and behavioural calibration of brief ABR stimuli are described. The average insert earphone thresholds for 25 young adults with normal hearing for 500, 1000, 2000, 4000 and 8000 Hz, 2-1-2 cycle tonebursts presented at 41 per second were: 24, 20, 23, 23 and 34 dB peak to peak equivalent (ppe) SPL (re 20 mPa), respectively. Average thresholds were about 30 dB ppeSPL for 100 ms clicks. Results were generally consistent with normative values reported in the literature.