Modifications of the MUlti stimulus test with Hidden Reference and Anchor (MUSHRA) for use in audiology

Abstract

Objective: Two modifications of the standardised MUlti Stimulus test with Hidden Reference and Anchor (MUSHRA), namely MUSHRA simple and MUSHRA drag&drop, were implemented and evaluated together with the original test method. The modifications were designed to maximise the accessibility of MUSHRA for elderly and technically non-experienced listeners, who constitute the typical target group in hearing aid evaluation. Design: Three MUSHRA variants were assessed based on subjective and objective measures, e.g. test–retest reliability, discrimination ability, time exposure and overall preference. With each method, participants repeated the task to rate the quality of several hearing aid algorithms four times. Study sample: Fifty listeners grouped into five subject classes were tested, including elderly and technically non-experienced participants with normal and impaired hearing. Normal-hearing, technically experienced students served as controls. Results: Both modifications can be used to obtain compatible rating results. Both were preferred over the classical MUSHRA procedure. Technically experienced listeners performed best with the modification MUSHRA drag&drop. Conclusions: The comprehensive comparison of the MUSHRA variants demonstrates that the intuitive modification MUSHRA drag&drop can be generally recommended. However, considering e.g. specific evaluation demands, we suggest a differentiated and careful application of listening test methods.

Key Words:

• MUSHRA
• perceptual evaluation
• subjective evaluation
• quality
• hearing aid algorithms

Acknowledgements

The authors would like to thank the Hörzentrum Oldenburg for recruiting suitable test persons for our study with their comprehensive listener database. We thank Matthias Vormann and Miriam Kropp from Hörzentrum Oldenburg for performing the measurements and their help with the calibration. We thank Markus Meis for his help with the data for the technology commitment and Nick Zacharov for providing code for the “eGauge” model calculating the assessor performance. We also thank Tobias Herzke, Giso Grimm, and Graham Coleman for their support with the Master Hearing Aid (MHA). We are very grateful for the helpful advices and fruitful discussions with Volker Hohmann.

Declaration of interests

The authors report that they have no conflicts of interest. This work was funded by (a) the project “Modellbasierte Horgeräte” (01EZ1127D) from the German Ministry of Education and Research (BMBF), (b) the research group “Individualisierte Hörakustik” (FOR1732) and (c) the Cluster of Excellence “Hearing4All” (EXZ1077), latter two from the German research foundation (DFG).