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.

Key Words:

• Medico-legal assessment
• hearing disability
• hearing handicap
• communication handicap
• speech perception
• auditory
• audio-visually
• interview
• discrimination tests
• Denmark

Acknowledgements

The authors thank Hilde Christin Wangen, department of audiology, Aarhus University Hospital for carrying out the majority of the audiological tests. The authors also thank Torben Poulsen, Centre for Applied Hearing Research, Technical University of Denmark for valuable discussions. Finally, the authors thank the anonymous reviewers for valuable comments.

Declaration of interest

This study was supported by the Oticon Foundation, grant number 12-1361. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Notes

1. The form and thereby this study use the term handicap though today it would be more appropriate to use the term activity limitations due to the International Classification of Functioning, Disability and Health presented by the World Health Organization in 2001 (WHO, 2013).

2. In Salomon & Parving (1985) the three listening situations are denoted by capital letters. In this study Roman numerals are used in order not to cause confusion between the first situation and the abbreviation ‘A’ used for auditory in Table 1.

3. The possible DSs for a test length of 20 words are: 0, 5, 10, 15… 100%, i.e. the resolution is 5%-point. For a test length of 25 words the possible DSs are: 0, 4, 8, 12… 100%, i.e. the resolution is 4%-point. The critical differences are defined at the possible DSs only. Thus, the grey areas in Figure 3 are results of interpolation of the defined critical differences.