Evaluation of the Clinical Benefit of a Transmitter for Contralateral Routing of Signals (CROS)

Study Overview
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Brief Summary
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This study will evaluate the clinical benefit of a transmitter for contralateral routing of signals. The benefit will be evaluated in noisy environments regarding speech intelligibility when the CROS system is adjusted to different microphone settings. Additionally, data regarding overall system stability, crash reboot rate, sound quality and connectivity will be obtained over a period of time to validate the CROS system in combination with smartphone and accessories. This study is a confirmatory study.

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.

Official Title
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Evaluation of the Clinical Benefit of a Transmitter for Contralateral Routing of Signals (CROS)

Conditions
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Hearing Loss

Intervention / Treatment
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* Other: BiCROS fitting
* Other: Monaural fitting
* Other: Unaided condition
* Other: CROS baseline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: hearing impaired adults, with & w/o hearing aids (experiences) good written and spoken (Swiss) German language skills ability to fill in a questionnaire conscientiously informed consent as documented by signature asymmetric hearing loss: one unaidable ear (min. N6 hearing loss) / the other ear with N3 or N4 hearing loss availability of Smartphone availability of TV or Tablet ability to operate and handle the investigational device ability to describe listening impressions/experiences and the use of the hearing aid Ability to produce a reliable hearing test result Exclusion Criteria: Contraindications to the medical device: aidable hearing loss on the intended CROS side acute tinnitus (in either one ear and occurrence less than three months) anatomical deformity of the CROS ear (e.g. absence of the auricle) Known hypersensitivity or allergy to materials of the investigational device any auricle deformities, that prevents secure placement of the (test) devices no willingness to test the investigational device system no willingness to test the investigational device system for at least 8h a day Hint for psychological problems from investigators point of view reported fluctuating hearing that could influence the test result reported symptoms of vertigo and dizziness by participants

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

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 Oldenburg Sentence test (OLSA), 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 poorer, unaidable ear and with a compatible hearing device on the other ear.<br>Other: Monaural fitting<br>* Each participant will be fitted with a hearing aid on the better hearing ear and no device on the poorer, 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>Other: CROS baseline<br>* Each participant will be fitted with the experimental CROS device on the poorer, unaidable ear and with a compatible device on the other ear. The difference to the BiCROS condition is the setup of the microphones in the CROS device and the compatible hearing device. This test condition is only tested for speech intelligibility in diffuse noise and 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 (SI) in noise (fix direction): BiCROS fitting vs. monaural hearing aid fitting | The primary objective of this clinical investigation is to evaluate whether a BiCROS fitting (better ear fitted with a hearing device, unaidable ear supplied with a CROS device) improves speech intelligibility in noise compared to a monaural fitting (just the aidable ear is supplied by a hearing aid), for adults with an asymmetric hearing loss, measured with the Oldenburg Sentence Test (OLSA). Results of the speech test will be the SRT (speech recognition threshold) in dB SNR (signal to noise ratio). The target speaker will be presented from 0° azimuth and is adaptive (start level at 65dB (A). The noise will be presented on the better ear at an azimuth of 90° or 270° (depending on the site of the better ear), at a level of 70 dB (A). | 2 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| SI in noise (fix direction): BiCROS fitting vs. unaided | A secondary objective of this clinical investigation is to evaluate whether a BiCROS fitting improves speech intelligibility in noise compared to an unaided condition, for adults with an asymmetric hearing loss, measured with the Oldenburg Sentence Test (OLSA). Results of the speech test will be the SRT (dB SNR). The target speaker will be presented from 0° azimuth and is adaptive (start level at 65dB (A). The noise will be presented on the better ear at an azimuth of 90° or 270° (depending on the site of the better ear), at a level of 70 dB (A). | 2 week | 
| SI in diffuse noise: BiCROS fitting vs. monaural fitting | A secondary objective of this clinical investigation is to evaluate whether a BiCROS fitting improves speech intelligibility by at least 1 dB SNR for 50% SRT in diffuse noise, compared to a monaural hearing aid fitting. The target speaker will be presented from 0° azimuth and is adaptive (start level at 65dB (A). The noise will be presented on the better ear at an azimuth of 90° or 270° (depending on the site of the better ear), at a level of 70 dB (A). | 2 weeks | 
| SI in diffuse noise: BiCROS fitting vs. unaided | A secondary objective of this clinical investigation is to evaluate whether a BiCROS fitting improves speech intelligibility by at least 1 dB SNR for 50% SRT in diffuse noise, compared to an unaided condition. The target speaker will be presented from 0° azimuth and is adaptive (start level at 65dB (A). The noise will be presented on the better ear at an azimuth of 90° or 270° (depending on the site of the better ear), at a level of 70 dB (A). | 2 weeks | 
| SI in diffuse noise: BiCROS vs. CROS baseline fitting | A secondary objective of this clinical investigation is to evaluate whether a BiCROS fitting improves speech intelligibility in diffuse noise compared with a CROS baseline fitting. CROS baseline means a fitting of an additional program with different hearing instrument microphone setup. The SI will be tested with the OLSA in diffuse noise. The target speaker will be presented from 0° azimuth and is adaptive (start level at 65dB (A). The noise will be presented on the better ear at an azimuth of 90° or 270° (depending on the site of the better ear), at a level of 70 dB (A). | 2 weeks | 
| SI in diffuse noise: CROS baseline fitting vs. unaided | A secondary objective of this clinical investigation is to evaluate whether a CROS baseline fitting improves speech intelligibility in diffuse noise compared with an unaided condition. The SI will be tested with the OLSA in diffuse noise. The target speaker will be presented from 0° azimuth and is adaptive (start level at 65dB (A). The noise will be presented on the better ear at an azimuth of 90° or 270° (depending on the site of the better ear), at a level of 70 dB (A). | 2 weeks | 
| SI in diffuse noise: CROS baseline fitting vs. monaural fitting | A secondary objective of this clinical investigation is to evaluate whether a CROS baseline fitting improves speech intelligibility in diffuse noise compared with a monaural fitting. The SI will be tested with the OLSA in diffuse noise. The target speaker will be presented from 0° azimuth and is adaptive (start level at 65dB (A). The noise will be presented on the better ear at an azimuth of 90° or 270° (depending on the site of the better ear), at a level of 70 dB (A). | 2 weeks | 
| SP in diffuse noise: monaural fitting vs. unaided | A secondary objective of this clinical investigation is to evaluate whether a monaural fitting improves speech intelligibility in diffuse noise compared with an unaided condition. The SI will be tested with the OLSA in diffuse noise. The target speaker will be presented from 0° azimuth and is adaptive (start level at 65dB (A). The noise will be presented on the better ear at an azimuth of 90° or 270° (depending on the site of the better ear), at a level of 70 dB (A). | 2 weeks | 
| Evaluation of Sound quality | A secondary objective of this study is to evaluate the participant's satisfaction of the sound quality of the experimental CROS device by a subjective rating during a three-week home trial period. Scale: very unsatisfied- unsatisfied- neither nor- satisfied- very satisfied | 3 weeks | 
| Evaluation of System stability | A secondary objective of this study is to evaluate the participant's satisfaction of the system stability of the experimental CROS device during a three-week home trial period. The participant shall report, if there are artefacts audible: never/ 1-2 times a week/ 3-6 times a week/ daily | 3 weeks | 
| Evaluation of streaming | A secondary objective of this study is to evaluate the participant's satisfaction of the streaming sound quality of the experimental CROS device, by a subjective rating during a three-week home trial period. Scale: very unsatisfied- unsatisfied- neither nor- satisfied- very satisfied | 3 weeks | 
| Evaluation of listening effort | A secondary objective is to evaluate the subjective listening effort in noise reported by the participant whilst wearing the experimental CROS device. Scale: not at all - slightly - somewhat - moderately - very - extremely | 3 weeks |