Evaluation of BiCROS Fitting Benefits

Evaluate the Benefit of a BiCROS Hearing Aid Fitting

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT05379231

Enrollment

Registered

2022-05-18

Start date

2022-07-11

Completion date

2023-03-21

Last updated

2025-06-11

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Unilateral Deafness

Brief summary

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.

Detailed description

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.

Interventions

DEVICEHearing aid fitting

A participant will wear a hearing aid with and without a CROS device on the unaidable ear.

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

OTHER

Masking

NONE

Masking description

Participants were wearing the BiCROS fitting during home trial, where no masking was possible. For in-lab tests, the CROS device was deactivated for the monaural condition, allowing for some masking. The unaided condition could not be masked. Participants were not aware which beamformer configuration was active during in-lab tests.

Intervention model description

All participants were wearing the BiCROS fitting during home trial, and tested in-lab with all conditions, randomized and counterbalanced (BiCROS fitting, monaural fitting, unaided).

Eligibility

Sex/Gender

ALL

Age

18 Years to 99 Years

Healthy volunteers

Yes

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

Design outcomes

Primary

Measure	Time frame	Description
Speech Intelligibility in Noise Measured With US Matrix Test (Noise From a Defined Loudspeaker)	At the appointment following the 4 weeks home trial each participant went on wearing the BiCROS fitting	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).

Secondary

Measure	Time frame	Description
Reports of Subjective Quality of Hearing as Assessed by the SSQ	At the appointment following the 4 weeks home trial each participant went on wearing the BiCROS fitting	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.
Reports of Subjective Quality of Hearing as Assessed by the Bern Benefit Questionnaires	At the appointment following the 4 weeks home trial each participant went on wearing the BiCROS fitting	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.
Speech Intelligibility in Noise Measured With US Matrix Test (Diffuse Noise)	At the appointment following the 4 weeks home trial each participant went on wearing the BiCROS fitting	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.
Subjective Preference of Hearing Aid Condition	At the appointment following the 4 weeks home trial each participant went on wearing the BiCROS fitting	3 alternative forced choice (A, B, no preference or ABX) paradigm with three repetitions for speech in noise presented via loudsepakers
Listening Effort in Noise Using 7 Point Scale (Holmes et. al., 2018)	At the appointment following the 4 weeks home trial each participant went on wearing the BiCROS fitting	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.
Sound Quality Ratings for Total Impression and Clarity Using Gabriellson et al (1990) Ratings Scales	At the appointment following the 4 weeks home trial each participant went on wearing the BiCROS fitting	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.

Countries

Canada

Participant flow

Pre-assignment details

2 participants had to be excluded from continuing in the study before assignment because they did not meet the inclusion criteria.

Participants by arm

Arm	Count
Complete Sample All participants will perform the same tests in all conditions. 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. BiCROS 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. Monaural hearing aid fitting: Each participant will be fitted with a hearing aid on the better hearing ear and no device on the unaidable ear. Unaided condition: No intervention, the participants are not fitted with a CROS device and/or hearing aid. Since the characteristics of each arm are unrelevant for the study outcome, there has been no separate analysis on each arm.	18
Total	18

Arm

Count

Complete Sample

All participants will perform the same tests in all conditions. 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. BiCROS 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. Monaural hearing aid fitting: Each participant will be fitted with a hearing aid on the better hearing ear and no device on the unaidable ear. Unaided condition: No intervention, the participants are not fitted with a CROS device and/or hearing aid. Since the characteristics of each arm are unrelevant for the study outcome, there has been no separate analysis on each arm.

Total

Withdrawals & dropouts

Period	Reason	FG000
Home Visit	Withdrawal by Subject	2
In-lab Visit	Withdrawal by Subject	2

Baseline characteristics

Characteristic	Complete Sample	—
Age, Continuous	74.6 years	—
BiCROS fitting candidate	18 Participants	—
Race and Ethnicity Not Collected	—	— Participants
Region of Enrollment Canada	18 participants	—
Sex: Female, Male Female	8 Participants	—
Sex: Female, Male Male	10 Participants	—

Adverse events

Event type	EG000 affected / at risk
deaths Total, all-cause mortality	0 / 22
other Total, other adverse events	2 / 22
serious Total, serious adverse events	0 / 22

Outcome results

Primary

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).