Evaluating a Hearing Loop Implementation for Live Orchestral Music

Live music creates a sense of connectedness in older adults, which can help alleviate the social isolation frequently associated with hearing loss and aging. However, most hearing-aid (HA) users are dissatisfied with the sound quality of live music and rate sound quality as important to them. Assistive listening systems are frequently independent of a user's HAs and fall short in tailoring to each individual's hearing loss. The present study thus tested whether the use of a hearing loop would improve sound quality during an orchestral concert.

Participants with symmetrical moderate-to-severe hearing loss were assigned to use Sonova-provided HAs with a telecoil (n = 20) or their own HAs (n = 8) without a telecoil during a performance by the Hamilton Philharmonic Orchestra. We changed loop input to use one of three feeds every 5 minutes: a mix of microphones from the hall's standard assistive feed on the first balcony (house condition), a mix of microphones located on the stage (stage condition), or no input to the loop (no feed). After each 5-minute interval, we collected sound quality and naturalness ratings for the previous 5 minutes.

Sound quality and naturalness ratings were highly related (rRM = 0.81), though each provided unique insight. Repeated measures analysis of variance found significant differences among the loop feed conditions for sound quality and naturalness, with the no feed condition significantly outperforming the house condition on sound quality [ t (18) = -3.73, adj. p = 0.005] and naturalness [ t (18) = -4.15, adj. p = 0.002]. Mixed effects models allowed us to retain the richness of a repeated observation dataset and provided point estimates of the overall quality and naturalness among conditions; however, assumption violations of normality and homoskedasticity prevented further interpretation.

Though HA-integrated assistive listening systems are a promising option for improving live music for people with hearing loss, a hearing loop does not seem to be crucial for orchestral music. Future directions include improving lyric understanding for music with vocals and customizing user experience via Bluetooth Low Energy Audio systems.