An interventional study of Hearing aid fitting in Unilateral Deafness, sponsored by Sonova AG. Completed at 2 sites in Canada. Open to participants aged 18 Years to 99 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-06-11.
Sponsored by Sonova AG · Not applicable, Interventional, and Other
22 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.
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.
609 studies on the registry are indexed under Deafness; 111 are open to participants now.
This study's enrollment of 22 is below the median of 40 across 411 interventional studies indexed under Deafness.
Browse Deafness studies →Sonova AG is the lead sponsor of 82 studies on the registry; 6 are open to participants now.
Of its 25 completed or terminated interventional studies of FDA-regulated products, 17 (68%) have results posted.
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Exclusion Criteria:
Each participant will be fitted with the experimental CROS device on the unaidable ear and with a compatible hearing aid on the other ear. A beamformer (directional microphone) will be enabled during this measurement. Although each ear receives a different device configuration depending on the condition, the participant is assigned as a whole, and assignment is not by ears.
Device: Hearing aid fitting
Each participant will be fitted with the experimental CROS device on the unaidable ear and with a compatible hearing aid on the other ear. The microphones will be omnidirectional. Although each ear receives a different device configuration depending on the condition, the participant is assigned as a whole, and assignment is not by ears.
Device: Hearing aid fitting
Each participant will be fitted with a hearing aid on the better hearing ear and no device on the unaidable ear. A beamformer (directional microphone) will be enabled during the measurement. Although each ear receives a different device configuration depending on the condition, the participant is assigned as a whole, and assignment is not by ears.
Device: Hearing aid fitting
Each participant will be fitted with a hearing aid on the better hearing ear and no device on the unaidable ear. The microphone will be omnidirectional. Although each ear receives a different device configuration depending on the condition, the participant is assigned as a whole, and assignment is not by ears.
Device: Hearing aid fitting
No intervention, the participants are not fitted with a CROS device and/or hearing aid.
A participant will wear a hearing aid with and without a CROS device on the unaidable ear.
Speech Intelligibility in Noise Measured With US Matrix Test (Noise From a Defined Loudspeaker)
Measuring the Signal to Noise Ratio change in decibels (dB) for speech from the front loudspeaker and noise from the better ear's side with the US matrix Test. 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 65 dB (A).
Time frame: At the appointment following the 4 weeks home trial each participant went on wearing the BiCROS fitting
Speech Intelligibility in Noise Measured With US Matrix Test (Diffuse Noise)
Measuring the Signal to Noise Ratio change in decibels (dB) for speech from the front loudspeaker in surrounding noise with the US Matrix Test. 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 from a circle of 8 surrounding speakers from 45° to 315° at a level of 65 dB (A) with the participant seated in the centre of the circle.
Time frame: At the appointment following the 4 weeks home trial each participant went on wearing the BiCROS fitting
Reports of Subjective Quality of Hearing as Assessed by the SSQ
Measured after home trial with the Speech, Spatial and Qualities of Hearing Scale-Benefit (Gatehouse, 2004). The scale ranges from -5 to 5, where negative values indicate that the condition under test is worse than the comparator, 0 indicates no change, and positive values indicate a benefit of the condition under test compared to the comparator.
Time frame: At the appointment following the 4 weeks home trial each participant went on wearing the BiCROS fitting
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). The scale ranges from -5 to 5, where negative values indicate that the condition under test is better wihtout the hearing aid, 0 indicates no change, and positive values indicate a benefit with the hearing aid.
Time frame: At the appointment following the 4 weeks home trial each participant went on wearing the BiCROS fitting
Sound Quality Ratings for Total Impression and Clarity Using Gabriellson et al (1990) Ratings Scales
Ratings of speech in noise presented via loudspeakers using Gabriellson et al (1990) Ratings Scales. Scales include Clarity and Total Impression, and range from 1 to 10. The higher the rating, the better the Clarity and Total Impression.
Time frame: At the appointment following the 4 weeks home trial each participant went on wearing the BiCROS fitting
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
Time frame: At the appointment following the 4 weeks home trial each participant went on wearing the BiCROS fitting
Listening Effort in Noise Using 7 Point Scale (Holmes et. al., 2018)
Measuring listening effort for speech in multi-talker babble presented via loudspeaker. The scale ranges from 1 to 7, and a higher rating indicates less listening effort.
Time frame: At the appointment following the 4 weeks home trial each participant went on wearing the BiCROS fitting
| Milestone | Complete Sample |
|---|---|
| Started | 20 |
| Completed | 18 |
| Not completed | 2 |
| Withdrew: Withdrawal by subject | 2 |
| Milestone | Complete Sample |
|---|---|
| Started | 20 |
| Bicros fitting with beamformer | 20 |
| Bicros fitting omni | 20 |
| Monaural hearing aid fitting with beamformer | 20 |
| Monaural hearing aid fitting omni | 20 |
| Unaided condition | 20 |
| Completed | 18 |
| Not completed | 2 |
| Withdrew: Withdrawal by subject | 2 |
Measuring the Signal to Noise Ratio change in decibels (dB) for speech from the front loudspeaker and noise from the better ear's side with the US matrix Test. 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 65 dB (A).
| dBSRT | BiCROS With Beamformer | BiCROS Omni | Monaural With Beamformer | Monaural Omni | Unaided |
|---|---|---|---|---|---|
| Speech Intelligibility in Noise Measured With US Matrix Test (Noise From a Defined Loudspeaker) | -8.8 ± 3.4 | -3.7 ± 2.9 | -9.2 ± 2.7 | -2.8 ± 2.5 | -0.1 ± 6.8 |
Measuring the Signal to Noise Ratio change in decibels (dB) for speech from the front loudspeaker in surrounding noise with the US Matrix Test. 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 from a circle of 8 surrounding speakers from 45° to 315° at a level of 65 dB (A) with the participant seated in the centre of the circle.
| dBSRT | BiCROS With Beamformer | BiCROS Omni | Monaural With Beamformer | Monaural Omni | Unaided |
|---|---|---|---|---|---|
| Speech Intelligibility in Noise Measured With US Matrix Test (Diffuse Noise) | -14.2 ± 3.3 | -8 ± 4.2 | -13.9 ± 3.6 | -9.3 ± 3 | -3.4 ± 9.4 |
Measured after home trial with the Speech, Spatial and Qualities of Hearing Scale-Benefit (Gatehouse, 2004). The scale ranges from -5 to 5, where negative values indicate that the condition under test is worse than the comparator, 0 indicates no change, and positive values indicate a benefit of the condition under test compared to the comparator.
| score on a scale | BiCROS |
|---|---|
| Speech | 2.48 ± 0.59 |
| Spatial | 1.16 ± 0.47 |
| Qualities | 2.55 ± 0.35 |
Measured after home trial with the Bern Benefit in Single-Sided Deafness Questionnaire (Komps et al, 2011). The scale ranges from -5 to 5, where negative values indicate that the condition under test is better wihtout the hearing aid, 0 indicates no change, and positive values indicate a benefit with the hearing aid.
| score on a scale | BiCROS |
|---|---|
| Reports of Subjective Quality of Hearing as Assessed by the Bern Benefit Questionnaires | 2.83 ± 0.76 |
Ratings of speech in noise presented via loudspeakers using Gabriellson et al (1990) Ratings Scales. Scales include Clarity and Total Impression, and range from 1 to 10. The higher the rating, the better the Clarity and Total Impression.
| score on a scale | BiCROS With Beamformer | BiCROS Omni | Monaural With Beamformer | Monaural Omni | Unaided |
|---|---|---|---|---|---|
| Clarity | 6.8 ± 2.4 | 5.2 ± 2.8 | 6.5 ± 2.3 | 4.8 ± 2.8 | 3.7 ± 3 |
| Total Impression | 6.1 ± 2.7 | 4.7 ± 2.8 | 6 ± 2.3 | 4.3 ± 2.5 | 3.7 ± 2.6 |
3 alternative forced choice (A, B, no preference or ABX) paradigm with three repetitions for speech in noise presented via loudsepakers
| Participants | BiCROS w/ Beamformer vs. Monaural w/ Beamformer | BiCROS Omni vs. Monaural Omni | BiCROS Omni vs. w/ Beamformer | Monaural Omni vs. w/ Beamformer |
|---|---|---|---|---|
| No preference | 7 | 11 | 2 | 4 |
| Monaural | 6 | 3 | 0 | 0 |
| BiCROS | 5 | 4 | 0 | 0 |
| Directional | 0 | 0 | 16 | 14 |
| Omnidirectional | 0 | 0 | 0 | 0 |
Measuring listening effort for speech in multi-talker babble presented via loudspeaker. The scale ranges from 1 to 7, and a higher rating indicates less listening effort.
| score on a scale | BiCROS With Beamformer | BiCROS Omni | Monaural With Beamformer | Monaural Omni | Unaided |
|---|---|---|---|---|---|
| Listening Effort in Noise Using 7 Point Scale (Holmes et. al., 2018) | 3.75 ± 1.8 | 4.9 ± 1.9 | 3.9 ± 1.6 | 5 ± 1.5 | 5.7 ± 1.8 |
Collected over From the first appointment the participant was enrolled and assessed, until the last appointment that concluded the home trial and study participation. The whole duration was about 5-6 weeks per participant.. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Complete Sample | 0/22 (0%) | 0/22 (0%) | 2/22 (9.1%) |
| Event | Complete Sample |
|---|---|
| Ear infectionEar and labyrinth disorders | 1/22 |
| Early withdrawal (unrelated)Surgical and medical procedures | 1/22 |
| Age, Continuous(years) | Complete Sample |
|---|---|
| Mean | 74.6 (61 to 91) |
| Sex: Female, Male(Participants) | Complete Sample |
|---|---|
| Female | 8 |
| Male | 10 |
| Race and Ethnicity Not Collected(Participants) | Complete Sample |
|---|
| Region of Enrollment(participants) | Complete Sample |
|---|---|
| Canada | 18 |
| BiCROS fitting candidate(Participants) | Complete Sample |
|---|---|
| Count of participants | 18 |
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Sonova AG