Amplification and Assistive Devices (AAD)
Eric Branda, AuD, PhD
Director, Applied Audiological Research
WS Audiology, United States
With the introduction of new hearing aid platforms and technology, it is important to investigate wearer benefits outside of the lab in everyday, real-world listening situations. Recently, a new hearing aid platform utilizing split signal processing was introduced. Experienced hearing aid wearers from three different countries were surveyed. Respondents were asked to rate the performance of a new signal processing strategy in comparison to their own, current hearing aids in real-world listening environments.
In this session, this new split-processing technology and results of a self-reported survey of wearer benefit are discussed.
Summary:
Rationale
Hearing aids use various algorithms to improve speech intelligibility in noise. Traditionally, hearing aids process environmental sounds as a single stream, applying the same amplification characteristics to sounds in the stream. These algorithms may work against each other, creating audible artifacts.
A new algorithm, called split processing, addresses these limitations using a different approach. Rather than processing a single stream, this approach splits the incoming sounds into two separate streams. This splitting enables processing of sounds coming from the back and front of the wearer separately and with different settings. This split processing increases the contrast between spatially separated sounds to assist speech understanding in noise.
Using a survey, we asked wearers if split processing resulted in any self-reported real-world listening benefits.
Methods
A survey was conducted with hearing aid wearers in three countries: United States, Germany and France. Hearing care professionals were asked to fit hearing aids with split processing to experienced hearing aid wearers. The hearing aids were fitted bilaterally using the manufacturer proprietary fitting algorithm. Respondents were asked to compare the new hearing aids to their own, currently worn devices (average age of current devices, four years). Respondents consisted of 37 wearers (18 in the US, eight in German, and 11 in France) with 13 females and 24 males all aged between 28 and 91 years old (mean age, 72 years).
The questionnaire consisted of six satisfaction questions, posed on a seven-point Likert-type scale (1 = “very unsatisfied”, 7 = “very satisfied”), and thirteen questions related to quality of life from the Speech, Spatial and Qualities of hearing questionnaire (SSQ). Respondents were asked to follow a specific wearing routine and base responses on their experience with the devices they had just finished wearing. The survey was administered in the following manner:
Following the final round, wearers were asked to determine preferences for six listening categories, using a forced choice approach.
Results
Results of the survey showed significant main effects of device, question and respondent (all p < .00001) with no effect of assessment number (satisfaction: p = .32, SSQ: p = .09). Tukey post-hoc analysis showed significant differences for four of the six satisfaction questions (p < .01) and a significant difference for nine of the thirteen SSQ questions (p < .01).
Preferences ranged from 73% to 81% for the specified categories, and an overall 78% preference for the new processing. Preference for split processing was significant (all p < .05) using a two-tailed binomial test with Bonferroni correction for multiple comparisons.
Conclusions
Using a survey, split processing in a new hearing aid was evaluated by 37 experienced wearers. Results demonstrated several significant improvements in self-reported benefit for real-world listening environments. Seventy-eight percent of respondents expressed a clear preference for devices with split processing over their own devices.