Evaluation of a frequency lowering hearing instrument algorithm using a non-inferiority test
Abstract
The primary goal of hearing instrument verification is to demonstrate an improvement on a relevant outcome. It is imprudent to implement an algorithm that improves one outcome while simultaneously degrading another. A traditional test typically uses a superiority hypothesis – H0: New = Conventional and H1: New ≠ Conventional. The absence of statistical significance may be interpreted incorrectly as an absence of clinically relevant differences. An alternative is to start the test with a non-inferiority hypothesis – H0: New < Conventional and H1: New ≥ Conventional. Cross-over designs are often employed because treatment differences are frequently measured within a subject rather than between subjects. Each test period should be long enough for the subject to become acclimatized to each processing change. With these conditions, it is possible to estimate, with the same test, the overall effect of the developed feature and also the period effect. The method of using a cross-over design with a non-inferiority analysis was applied in the testing of a new frequency lowering algorithm. Improved high-frequency functional gain and fricative discrimination was observed. Significant non-inferior SSQ scores between the processing on and off were seen while no period effect was found. These results provide a good approximation of ‘real world’ acceptance.
References
Cox, R.M. (2005). “Evidence-based practice in provision of amplification,” J Am Acad Audiol. 2005, 16, 419-38.
Cox, R.M., and Alexander, G.C. (1995). “The abbreviated profile of hearing aid benefit,” Ear. Hearing, 16, 176-186.
CPMP: Committee for Proprietary Medicinal Products (2000). “Points to consider on switching between superiority and non-inferiority,” European Medicines Agency (EMEA), CPMP/EWP/482/99.
D'Agostino, R.B. Sr., Massaro, J.M., and Sullivan, L.M. (2003). “Non-inferiority trials: design concepts and issues – the encounters of academic consultants in statistics,” Stat. Med., 22, 169-186.
Dawes, P., Hopkins, R., and Munro, K.J. (2013). “Placebo effects in hearing-aid trials are reliable,” Int. J. Audiol., 52, 472-477.
Ellis, R.J. (2012) “Benefit and predictors of outcome from frequency compression hearing aid use,” PhD thesis, University of Manchester, UK.
Gatehouse, S., and Noble, W. (2004). “The speech, spatial and qualities of hearing scale (SSQ),” Int. J. Audiol., 43, 85-99.
Hills, M., and Armitage, P. (1979). “The two-period cross-over clinical trial,” Br. J. Clin. Pharmacol., 8, 7-20.
ITU-R (2003). Recommendation BS.1534: Method for the subjective assessment of intermediate quality levels of coding systems. International Telecommunications Union, Geneva, Switzerland.
Jensen, N.S., Akeroyd, M.A., Noble, W., and Naylor, G. (2009). “The Speech, Spatial and Qualities of Hearing scale (SSQ) as a benefit measure,” NCRAR conference on The Ear-Brain System: Approaches to the Study and Treatment of Hearing Loss, Portland, October 2009 (poster).
Jones, B., Jarvis, P., Lewis, J.A., and Ebbutt, A.F. (1996). “Trials to assess equivalence: the importance of rigorous methods,” Brit. Med. J., 313, 36-39.
Köbler, S., Lindblad, A.C., Olofsson, A., and Hagerman, B. (2010). “Successful and unsuccessful users of bilateral amplification: differences and similarities in binaural performance,” Int. J. Audiol., 49, 613-627.
Kuk, F., Keenan, D., Korhonen, P., and Lau, CC. (2009). “Efficacy of linear frequency transposition on consonant identification in quiet and in noise,” J. Am. Acad. Audiol., 20, 465-479.
Noble, W., and Gatehouse, S. (2006). “Effects of bilateral versus unilateral hearing aid fitting on abilities measured by the Speech, Spatial, and Qualities of Hearing Scale (SSQ),” Int. J. Audiol., 45, 172-181.
Parsa, V., Scollie, S., Glista, D., and Seelisch, A. (2013). “Nonlinear frequency compression: effects on sound quality ratings of speech and music,” Trends Amplif., 17, 54-68.
Pocock, S.J. (2003). “The pros and cons of noninferiority trials,” Fundam. Clin. Pharmacol., 17, 483-490.
Simpson, A., Hersbach, A.A., and McDermott, H.J. (2006). “Frequency-compression outcomes in listeners with steeply sloping audiograms,” Int. J. Audiol., 45, 619-629.
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