Muddy, muddled, or muffled? Understanding the perception of audio quality in music by hearing aid users

Abstract

Introduction: Previous work on audio quality evaluation has demonstrated a developing convergence of the key perceptual attributes underlying judgments of quality, such as timbral, spatial and technical attributes. However, across existing research there remains a limited understanding of the crucial perceptual attributes that inform audio quality evaluation for people with hearing loss, and those who use hearing aids. This is especially the case with music, given the unique problems it presents in contrast to human speech.

Method: This paper presents a sensory evaluation study utilising descriptive analysis methods, in which a panel of hearing aid users collaborated, through consensus, to identify the most important perceptual attributes of music audio quality and developed a series of rating scales for future listening tests. Participants (N = 12), with a hearing loss ranging from mild to severe, first completed an online elicitation task, providing single-word terms to describe the audio quality of original and processed music samples; this was completed twice by each participant, once with hearing aids, and once without. Participants were then guided in discussing these raw terms across three focus groups, in which they reduced the term space, identified important perceptual groupings of terms, and developed perceptual attributes from these groups (including rating scales and definitions for each).

Results: Findings show that there were seven key perceptual dimensions underlying music audio quality (clarity, harshness, distortion, spaciousness, treble strength, middle strength, and bass strength), alongside a music audio quality attribute and possible alternative frequency balance attributes.

Discussion: We outline how these perceptual attributes align with extant literature, how attribute rating instruments might be used in future work, and the importance of better understanding the music listening difficulties of people with varied profiles of hearing loss.

Keywords: audio quality evaluation; hearing aids; hearing loss; music; perception.

Figure 1

Total use of 20 most frequent terms across aided and unaided listening.

Figure 2

Wordcloud visualization provided to participants in FG1, presenting terms used more than three times in the individual elicitation task; there is no correspondence between word size and frequency of use.

Figure 3

Spatial map of perceptual terms, arranged by participants in FG1. Loose groupings of terms were proposed by the researchers to facilitate discussions in FG2, and these are visualized.

Figure 4

Boxplot visualization of ratings, across nine attributes, for accuracy of definition and ease of use for the attribute scales.