Evaluation of BiCROS Fitting Benefits

Study Overview
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Brief Summary
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23 candidates for BiCROS hearing aids will be recruited and fitted with a hearing aid and a CROS device. Following a real-world trial, each participant will be tested on a range of outcome measures including speech recognition in noise, ratings of listening effort, and ratings of preference.

Detailed Description
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Unilateral Hearing Loss (UHL) can be defined as any degree of permanent hearing loss on one ear with normal hearing in the opposite ear. Unilateral hearing loss can be debilitating associated with audiological, psychosocial and educational challenges. Audiological challenges include the reduced ability to localize sounds, reduced awareness on the unaidable side and difficulties hearing in noise or at a distance. One solution for unaidable UHL is Contralateral Routing of Signals (CROS) and Bilateral Contralateral routing of signals (BiCROS) using a so-called CROS transmitter together with a hearing aid. The rationale for this clinical investigation is to collect clinical data with a rechargeable CROS transmitter to evaluate the benefits of a BiCROS fitting compared to the alternative treatment option, the monaural hearing aid fitting, and to no treatment in noisy listening situations. Hearing tests, ear impressions and hearing aid fitting visits are mainly conducted at the National Centre for Audiology in London, Ontario. Those visits are available at the Sonova Innovation Centre Toronto in Mississauga, Ontario, upon request. Outcome measurements are only conducted at the National Centre for Audiology in London, Ontario.

Official Title
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Evaluate the Benefit of a BiCROS Hearing Aid Fitting

Conditions
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Unilateral Deafness

Intervention / Treatment
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* Other: BiCROS fitting
* Other: Monaural hearing aid fitting
* Other: Unaided condition


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: unaidable hearing loss in worse ear (>N6) aidable hearing loss (N3 to N5) on the other ear fluent English speaker Exclusion Criteria: - aidable hearing loss in both ears

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 99 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Speech Intelligibility with CROS device<br>The focus of this study is on Speech Intelligibility (SI), evaluated by the US Matrix Test, which measures a speech recognition threshold (SRT) in dB SNR (signal to noise ratio). Therefore each participant will perform the tests with the experimental rechargeable CROS transmitter (CROS) in different interventions, like comparison to monaural fitting and unaided condition. All participants will perform the same tests. The order of the intervention in the speech test is randomized, but will be performed in the same visit by each participant. | Other: BiCROS fitting<br>* Each participant will be fitted with the experimental CROS device on the unaidable ear and with a compatible hearing aid on the other ear.<br>Other: Monaural hearing aid fitting<br>* Each participant will be fitted with a hearing aid on the better hearing ear and no device on the unaidable ear. Monaural hearing aid fitting acts as control intervention.<br>Other: Unaided condition<br>* No treatment, i.e. the participants are not fitted with a CROS device and/ or hearing aid. Unaided condition acts as control intervention.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Speech intelligibility in Noise measured with US Matrix Test (noise from a defined loudspeaker) | Measuring the Signal to Noise Ratio change in decibels for speech from the front loudspeaker and noise from the better ear's side | 7 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Speech intelligibility in Noise measured with US Matrix Test (diffuse noise) | Measuring the Signal to Noise Ratio change in decibels for speech from the front loudspeaker in surrounding noise | 7 months | 
| Reports of Subjective quality of hearing as assessed by the SSQ | Measured after home trial with the Speech, Spatial and Qualities of Hearing Scale (Gatehouse, 2004) | 7 months | 
| Reports of Subjective quality of hearing as assessed by the Bern Benefit Questionnaires | Measured after home trial with the Bern Benefit in Single-Sided Deafness Questionnaire (Komps et al, 2011) | 7 months | 
| Sound quality ratings for Total Impression and Clarity using Gabriellson et al (1990) Ratings Scales | Ratings of speech in quiet and in noise presented via loudspeakers | 7 months | 
| Subjective preference of hearing aid condition | 3 alternative forced choice (A, B, no preference or ABX) paradigm with three repetitions for speech in noise presented via loudsepakers | 7 months | 
| Listening effort in noise using 7 point scale (Johnson et al, 2015) | Measuring listening effort for speech in multi-talker babble presented via loudspeaker | 7 months |