A Comparison Between Wireless CROS and Bone-anchored Hearing Devices for Single-Sided Deafness: A Pilot Study

Manohar Bance

Status: Completed

Conditions: Unilateral Hearing Loss; Unilateral Deafness

Treatments: Device: Bone-anchored hearing device (BAHD); Device: CROS hearing aid

Study type: Interventional

Funder types: Other

Identifiers

NCT01715948

CDHA-RS/2013-118

Details and patient eligibility

About

People with single-sided deafness (SSD) have significant hearing loss in one ear and normal or near normal hearing in the other ear. Those living with SSD experience several communication difficulties, particularly when listening to speech in the presence of background noise. This problem is worse in situations where the noise is on the side of the good ear and the speech is on the side of the poor ear.

The Bone-anchored hearing device (BAHD) and the Contralateral Routing of Signals (CROS) hearing aid are two intervention methods designed to improve hearing in people who have significant hearing loss in one ear only. The BAHD is a surgically implanted device which also includes an external processor; sounds from the poor ear are transmitted to the good ear through skull vibrations. The CROS does not involve surgery; instead a hearing aid is fitted behind each ear, and the sounds on the side of the poor ear are wirelessly transmitted to the good ear.

The majority of previous studies comparing the BAHD to the CROS have used older CROS models with basic technology and a wire along the neck to send sounds from the poor ear to the good ear. There is a lack of studies comparing newer digital wireless CROS hearing aids to the BAHD. The current research will compare the effect of the BAHD and CROS hearing aid on speech perception scores when listening to speech in quiet and in noise. The research will also investigate participants' reported benefits with each device during everyday situations. In order to compare the BAHD and CROS, individuals who already have been implanted with a BAHD will be given a trial period with a new wireless digital CROS hearing aid.

The research hypothesis states that the CROS hearing aid will be as equally beneficial or greater than the BAHD in improving hearing and participant benefit. If the findings support the hypothesis that the CROS offers just as much benefits as the BAHD, or is an even better alternative, more individuals with SSD may choose to avoid surgery and decide to receive a CROS hearing aid instead.

Full description

Users of the BAHD will be given a 2-week trial period with the Unitron Tandem CROS hearing aid. Participants will be randomly assigned to wear either their BAHD for two weeks or the trial CROS for two weeks. There will be a total of three visits made to the clinic.

During each visit:

• Participants' hearing will be tested (either with the BAHD, the CROS, or without wearing any device).
• Speech perception ability will be tested in quiet and in noise conditions (either while wearing the BAHD, the CROS, or no device).
• Participants will be asked to complete two standardized questionnaires on the perceived benefits that the BAHD or the CROS provides.

In addition, participants will be asked to fill out a short diary form every day, for a two-week period, to report the situations in which they wore the device.

Enrollment: 9 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Adults with unilateral deafness (hearing loss in only one ear) who received BAHD surgery less than 3 years ago
• Severe to profound hearing loss in the poor ear and normal hearing in the good ear
• English speaking

Exclusion criteria

• Adults who underwent BAHD surgery more than 3 years ago
• Adults with hearing loss in both ears
• Adults who received a BAHD to treat a condition other than unilateral deafness (such as bilateral conductive hearing loss)

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Single Group Assignment

Masking: None (Open label)

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9 participants in 2 patient groups

CROS hearing aid

Experimental group

Description:

The CROS uses two hearing aids that fit behind each ear. The hearing aid fitted with a retainer earhook on the side of the poor ear houses a microphone and a transmitter. The hearing aid fitted on the normal ear side houses a receiver that is connected to a slim tube and open ear tip. The CROS does not amplify sound but rather transmits sound from the side of the unaidable ear to the contralateral ear, overcoming the head shadow effect that presents with SSD.

Treatment:

Device: CROS hearing aid

Bone-anchored hearing device (BAHD)

Experimental group

Description:

The BAHD (such as the Baha by Cochlear or Bone-Bridge by MED-EL) also helps to alleviate the negative effect of head shadow and the difficulty with speech perception in noise that present with SSD. Also known as an osseointegrated aural prosthesis, the BAHD is implanted in individuals with SSD to stimulate the ear with the normal cochlea. The BAHD requires that a titanium screw be surgically implanted in the temporal bone on the side of the poor ear. This titanium screw is connected to a percutaneous abutment. An electromechanical sound processor (external transducer) is coupled onto the abutment and can be removed when necessary. Sound can now be routed to the better ear by transcranial bone conduction.

Treatment:

Device: Bone-anchored hearing device (BAHD)