Ellen Raben Pedersen

Sound Exposure of Symphony Orchestra Musicians

BACKGROUND Assessment of sound exposure by noise dosimetry can be challenging especially when measuring the exposure of classical orchestra musicians where sound originate from many different instruments. A new measurement method of bilateral sound exposure of classical musicians was developed and used to characterize sound exposure of the left and right ear simultaneously in two different symphony orchestras. OBJECTIVES To measure binaural sound exposure of professional classical musicians and to identify possible exposure risk factors of specific musicians. METHODS Sound exposure was measured with microphones mounted on the musicians ears and recorded digitally. The recorded sound was analysed and the specific sound exposure of the left and the right ear was determined for the musicians. A total of 114 measurements covering 106 h were recorded in two symphony orchestras. RESULTS Sound exposure depends significantly on the specific instrument and the repertoire played by the exposed musician. Concerts, group rehearsals and individual practice were all significant contributors to the sound exposure. The highest L(Aeq) of 86 -98 dB was found among the brass players. High string players were exposed from 82 to 98 dBA and their left ear was exposed 4.6 dB more than the right ear. Percussionists were exposed to high sound peaks >115 dBC but less continuous sound exposure was observed in this group. Musicians were exposed up to L(Aeq8h) of 92 dB and a majority of musicians were exposed to sound levels exceeding L(Aeq8h) of 85 dB. CONCLUSIONS Binaural recording of the individual sound exposure showed that orchestra musicians could be exposed differently to the left and right ear and that they were primarily exposed from their own instruments. Specific repertoires as well as the specific instrument determine the level of exposure.

Hearing Loss in Relation to Sound Exposure of Professional Symphony Orchestra Musicians

Objectives: The objectives of this study were to: (1) estimate the hearing status of classical symphony orchestra musicians and (2) investigate the hypothesis that occupational sound exposure of symphony orchestra musicians leads to elevated hearing thresholds. Design: The study population comprised all the musicians from five symphony orchestras. Questionnaires were filled in by 337 subjects, and 212 subjects performed an audiometric test. For a group of 182 musicians (363 ears) the results of the audiometry was analyzed in relation to the individual exposure, which was estimated on the basis of sound measurements and questionnaire data regarding the exposure time. The mean hearing threshold at the frequencies 3, 4, and 6 kHz, corrected for age and sex, was used as outcome. Results: The musician ears with the highest exposure (29 of 363) had an additional threshold shift of 6.3 dB compared with the 238 ears with lowest exposure. The observed hearing loss of musicians was smaller compared with the noise-induced permanent threshold shift (NIPTS) predicted from ISO1999. A remaining confounding effect of age after ISO7029 age corrections could be observed to explain the difference in observed and predicted NIPTS. However, the observed hearing loss difference between the left and the right ear of musicians was 2.5 dB (95% confidence interval 1.5–3.6), which was similar to the NIPTS predicted from ISO1999. Most of the musicians had better hearing at 3, 4, and 6 kHz for age than expected, however, 29 ears with the highest exposure above 90.4 dBA with a mean exposure time of 41.7 years had significantly elevated hearing thresholds. Trumpet players and the left ear of first violinists had significantly elevated hearing thresholds compared with other musicians. Conclusion: Most of the symphony orchestra musicians had better hearing than expected but they had a work-related risk of developing additional noise-induced hearing loss. The additional NITPS of the left ear compared with the right ear was at the expected level based on the cumulated sound exposure and ISO1999, indicating that performing music may induce hearing loss to the same extent as industrial noise.

A European Perspective on Auditory Processing Disorder-Current Knowledge and Future Research Focus

Current notions of “hearing impairment,” as reflected in clinical audiological practice, do not acknowledge the needs of individuals who have normal hearing pure tone sensitivity but who experience auditory processing difficulties in everyday life that are indexed by reduced performance in other more sophisticated audiometric tests such as speech audiometry in noise or complex non-speech sound perception. This disorder, defined as “Auditory Processing Disorder” (APD) or “Central Auditory Processing Disorder” is classified in the current tenth version of the International Classification of diseases as H93.25 and in the forthcoming beta eleventh version. APDs may have detrimental effects on the affected individual, with low esteem, anxiety, and depression, and symptoms may remain into adulthood. These disorders may interfere with learning per se and with communication, social, emotional, and academic-work aspects of life. The objective of the present paper is to define a baseline European APD consensus formulated by experienced clinicians and researchers in this specific field of human auditory science. A secondary aim is to identify issues that future research needs to address in order to further clarify the nature of APD and thus assist in optimum diagnosis and evidence-based management. This European consensus presents the main symptoms, conditions, and specific medical history elements that should lead to auditory processing evaluation. Consensus on definition of the disorder, optimum diagnostic pathway, and appropriate management are highlighted alongside a perspective on future research focus.

User-operated speech in noise test: Implementation and comparison with a traditional test

Abstract Objective: The purpose of this study was to implement and evaluate a user-operated speech in noise test. Design: The test is based on the Danish speech material Dantale II, which consists of five words sentences (18). For each word presented the subject selected a response from ten alternative words. Two versions of the test were made: one with and one without the possibility that for each word presented the subject could answer “I do not know” (?-button). Using a listening test the two versions were evaluated against a traditional test, where the subjects orally repeated the words that were perceived. Study sample: Twenty-four normal-hearing subjects. Results: The speech intelligibility as a function of the signal-to-noise ratio can be described by logistic functions in the different user-operated tests and in the traditional test. The logistic parameters obtained from the user-operated test with the ?-button agree with the parameters obtained in a traditional test. The homogeneity of the speech material is uninfluenced when the material is used in a user-operated test. Conclusions: It is reasonable to use the Dantale II speech material for a user-operated speech in noise test, and the use of the ?-button is favourable.

Implementation and evaluation of a Danish test battery for auditory processing disorder in children

Abstract Objective: This study presents a Danish test battery for auditory processing disorder (APD). The tests were evaluated as to normative cut-off values (pass-fail criteria) and their test–retest reliability. Design: The battery consists of four behavioural tests: the filtered words (FW) test, the dichotic digits (DD) test, the gap detection (GD) test and the binaural masking level difference (BMLD) test. The tests were evaluated through listening experiments on children with no known history of auditory problems. Study sample: The normative cut-off values were obtained from 158 children (75 boys and 83 girls, aged 6–16 years), whereas the test–retest reliability was obtained from 20 children (10 boys and 10 girls, aged 6–11 years). Results: For each of the four tests one to four different cut-off values were determined depending on whether the scores from the two ears and the different age groups could be pooled. For each of the four tests the test–retest reliability was found to be satisfactory. The test–retest reliability was highest for the FW and the DD test. Conclusions: A Danish APD test battery is now available for clinical use with normative data.

A user-operated audiometry method based on the maximum likelihood principle and the two-alternative forced-choice paradigm

Abstract Objective: To create a user-operated pure-tone audiometry method based on the method of maximum likelihood (MML) and the two-alternative forced-choice (2AFC) paradigm with high test-retest reliability without the need of an external operator and with minimal influence of subjects’ fluctuating response criteria. User-operated audiometry was developed as an alternative to traditional audiometry for research purposes among musicians. Design: Test-retest reliability of the user-operated audiometry system was evaluated and the user-operated audiometry system was compared with traditional audiometry. Study sample: Test-retest reliability of user-operated 2AFC audiometry was tested with 38 naïve listeners. User-operated 2AFC audiometry was compared to traditional audiometry in 41 subjects. Results: The repeatability of user-operated 2AFC audiometry was comparable to traditional audiometry with standard deviation of differences from 3.9 dB to 5.2 dB in the frequency range of 250–8000 Hz. User-operated 2AFC audiometry gave thresholds 1–2 dB lower at most frequencies compared to traditional audiometry. Conclusions: User-operated 2AFC audiometry does not require specific operating skills and the repeatability is acceptable and similar to traditional audiometry. User operated 2AFC audiometry is a reliable alternative to traditional audiometry.

European 17 countries consensus endorses more approaches to APD than reported in Wilson 2018

It was a pleasure reading Wilson’s paper: “Evolving the concept of APD” (2018) insightful article on different approaches to APD set to promote understanding of the disorder. The interpretation of ...

The Danish test battery for auditory processing disorder evaluated with patient and control data

Abstract Objective: This study evaluates the Danish test battery for auditory processing disorder (APD). The battery consists of four behavioural tests, two speech and two non-speech stimuli tests. The evaluation includes determination of: (1) new cut-off values (pass-fail criteria), (2) the sensitivity and the specificity of the entire test battery and (3) the failure rate of different test combinations. Design: For each test in the battery, cut-off values were determined using the weighted Youden index. Applying the newly derived cut-off values, the distribution of failing specific test combinations was determined. Study sample: A group of 112 children diagnosed with APD (57 boys, 55 girls, aged 6–16 years) and a control group containing 158 children without auditory problems (75 boys, 83 girls, aged 6–16 years). Results: Cut-off values for different weights of the sensitivity and the specificity have been determined. Using the criterion that at least two tests have to be failed for APD to be suspected, the sensitivity and the specificity of the entire test battery were 95.3% and 91.6%, respectively. Some test combinations were found to have higher failure rates than others. Conclusions: Due to the high sensitivity and specificity the test battery has good predictive value in APD assessment.AbstractObjective: This study evaluates the Danish test battery for auditory processing disorder (APD). The battery consists of four behavioural tests, two speech and two non-speech stimuli tests. The evaluation includes determination of: (1) new cut-off values (pass-fail criteria), (2) the sensitivity and the specificity of the entire test battery and (3) the failure rate of different test combinations.Design: For each test in the battery, cut-off values were determined using the weighted Youden index. Applying the newly derived cut-off values, the distribution of failing specific test combinations was determined.Study sample: A group of 112 children diagnosed with APD (57 boys, 55 girls, aged 6–16 years) and a control group containing 158 children without auditory problems (75 boys, 83 girls, aged 6–16 years).Results: Cut-off values for different weights of the sensitivity and the specificity have been determined. Using the criterion that at least two tests have to be failed for APD to be suspected, the...

Reproducibility of Dual-Microphone Voice Range Profile Equipment

Purpose The aim of this study was to add further knowledge about the usefulness of the Voice Range Profile (VRP) assessment in clinical settings and research by analyzing VRP dual-microphone equipment precision, reliability, and room effect. Method Test-retest studies were conducted in an anechoic chamber and an office: (a) comparing sound pressure levels (SPLs) from a dual-microphone VRP device, the Voice Profiler, when given the same input repeatedly (test-retest reliability); (b) comparing SPLs from 3 devices when given the same input repeatedly (intervariation); and (c) assessing the room effect. Results (a) The mean standard deviation across 17 measurement points was 0.7 dB for 1 device. (b) One device was less precise than the other 2 devices. All devices presented high SPLs at low frequencies compared with the reference. (c) Mean SPLs were almost equal in the anechoic chamber and the office. Conclusions The high test-retest reliability of the dual-microphone VRP equipment, especially in general office surroundings, is a positive finding. Attention must be paid to specific factors such as using the same device when comparing the same voice before and after treatment, caution in headset placement, and manual recalibrations when automatic recalibration occurs. We suggest recalibrations verified with a reference source at regular intervals.

Speech perception in medico-legal assessment of hearing disabilities

Abstract Objective: Examination of Danish data for medico-legal compensations regarding hearing disabilities. The study purposes are: (1) to investigate whether discrimination scores (DSs) relate to patients’ subjective experience of their hearing and communication ability (the latter referring to audio-visual perception), (2) to compare DSs from different discrimination tests (auditory/audio-visual perception and without/with noise), and (3) to relate different handicap measures in the scaling used for compensation purposes in Denmark. Design: Data from a 15 year period (1999–2014) were collected and analysed. Study sample: The data set includes 466 patients, from which 50 were omitted due to suspicion of having exaggerated their hearing disabilities. Results: The DSs relate well to the patients’ subjective experience of their speech perception ability. By comparing DSs for different test setups it was found that adding noise entails a relatively more difficult listening condition than removing visual cues. The hearing and communication handicap degrees were found to agree, whereas the measured handicap degrees tended to be higher than the self-assessed handicap degrees. Conclusions: The DSs can be used to assess patients’ hearing and communication abilities. The difference in the obtained handicap degrees emphasizes the importance of collecting self-assessed as well as measured handicap degrees.