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Bimodal Zoom


- candidate number20918
- NTR NumberNTR4901
- ISRCTNISRCTN no longer applicable
- Date ISRCTN created
- date ISRCTN requested
- Date Registered NTR13-nov-2014
- Secondary IDs METC azZM/UM: 141130
- Public TitleBimodal Zoom
- Scientific TitleDirectional microphone systems for bimodal listeners
- ACRONYM
- hypothesisFor cochlear implanted (CI) patients speech recognition in noise still remains one of the most challenging tasks. One way to improve performance in noise is to benefit from binaural hearing (hearing with two ears). For individuals with residual contralateral hearing, a CI in one ear can be combined with an acoustic hearing aid (HA) in the other ear, known as bimodal hearing. For individuals without residual hearing a second CI can be an opportunity in the rare case. This is known as bilateral hearing. A second way to improve speech recognition in noise is to improve the quality of the signal before it is offered to the ear. To that end directional microphone systems are designed as they focus on the speech signal in front and reduce the noise from other directions. Nowadays, directional microphone algorithms are available for HA’s as well as for CI’s. Both approaches (binaural hearing and directional systems) are considered complementary, however they are not yet evaluated conjointly. Therefore the hypothesis assessed in this study is that directional microphone systems can improve speech recognition performance in binaural (bimodal or bilateral) cochlear implant users.
- Healt Condition(s) or Problem(s) studiedHearing aid, Cochlear implant
- Inclusion criteria1. capacitated adult (>18 years of age)
2. patient of CI-team South-East Netherlands
3. user of a unilateral cochlear implant (CI) of the brand Advanced Bionics (AB)
4. first fit CI >= 6 months ago
5. wearing CI speech processor (almost) always (i.e. circa 10 hours a day)
6. wearing a contralateral hearing aid >50% of the time (i.e. circa 5 hours a day)
7. able to perform the speech-in-noise test (i.e. speech recognition in quiet <50%)
8. willing and able to visit hospital and participate in testing
9. agreed to participate in this study (by informed consent)
- Exclusion criteria1. non Dutch speaking
2. < 18 years of age or incapacitated
3. bilateral cochlear implant user (CI+CI)
- mec approval receivedyes
- multicenter trialno
- randomisedyes
- masking/blindingSingle
- controlNot applicable
- groupCrossover
- TypeSingle arm
- Studytypeintervention
- planned startdate 1-jan-2015
- planned closingdate1-jun-2017
- Target number of participants24
- InterventionsDuring a single test session subjects are provided with the latest speech processor for the CI ear and a state-of-the-art hearing aid in the other ear allowing different microphone configurations: standard omnidirectional processing versus directional multi-microphone processing.
- Primary outcomeThe primary outcome is the effect of microphone configuration on speech recognition performance in noise. Hereby two main effects are distinguished:
- Directional effect, defined as the difference between the standard omnidirectional configuration, and the directional multi-microphone system in both CI and HA.
- Asymmetric effect, defined as the difference between a symmetric (directional multi-microphone system in both CI and HA) and an asymmetric directional configuration (standard omnidirectional microphone in HA and directional multi-microphone system in CI).
- Secondary outcomeSecondary outcomes in this study are:
- Effect of masker type, defined as the performance difference between a stationary speech-shaped background noise and a fluctuating competing talker.
- Listening effort, defined as the effort it takes to listen to speech in noise in the different directional and masking conditions.
- Timepoints
- Trial web site
- statusrecruitement status not public
- CONTACT FOR PUBLIC QUERIESDrs. E.M.J. Devocht
- CONTACT for SCIENTIFIC QUERIESProf. dr. R.J. Stokroos
- Sponsor/Initiator Maastricht University Medical Center (MUMC+)
- Funding
(Source(s) of Monetary or Material Support)
Maastricht University Medical Center (MUMC+), Advanced Bionics
- PublicationsN/A
- Brief summaryRationale:
Cochlear implantation (CI) has become standard practice to restore hearing in severely hearing-impaired patients by providing multi-channel electrical stimulation to the auditory nerve. Although CI-patients can achieve high levels of speech recognition in quiet, speech recognition in noise still remains one of the most challenging tasks. One way to improve performance in noise is to benefit from binaural hearing (hearing with two ears). For individuals with residual contralateral hearing, a CI in one ear can be combined with an acoustic hearing aid (HA) in the other ear. This is known as bimodal hearing. For individuals without residual hearing a second CI can be an opportunity in the rare case. This is known as bilateral hearing. A second way to improve speech recognition in noise is to improve the quality of the signal before it is offered to the ear. To that end directional microphone systems are designed as they focus on the speech signal in front and reduce the noise from other directions. Nowadays, directional microphone algorithms are available for HA’s as well as for CI’s. Both approaches (binaural hearing and directional systems) are considered complementary, however they are not yet evaluated conjointly.

Objective:
Evaluate the performance of directional microphone systems in binaural (bimodal and bilateral) cochlear implant users

Study population:
One group consists of users of a cochlear implant (CI) in one ear and a conventional hearing aid (HA) in the other ear. The other group consist users of a cochlear implant (CI) in both ears.

Study design:
A cross-over repeated measures design is carried out to single-blind evaluate the performance of directional microphone systems. During two test sessions bimodal subjects are provided with the latest speech processor for the CI ear and a state-of- the-art hearing aid in the other ear. The bilateral group will be provided with the latest CI speech processor in both ears during a single test session. Both CI and HA devices allow different microphone configurations: standard omnidirectional processing and directional multi- microphone processing in each ear separately (monaural) or combined cross ears (binaural). For each directional setting, speech perception in noise is assessed using two different masking materials (stationary noise versus fluctuating talker).

Primary study parameter:
The primary outcome is the effect of microphone configuration on speech recognition performance in noise.

Secondary study parameters:
Secondary outcomes in this study are bimodal benefit, the effect of masker type and listening effort. Results between the two patient groups, bimodal versus bilateral, will be compared.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: There are no known health risks associated with participation in this study. CE-marked hearing devices (CI and HA) are used within the scope of standard care. Participation however takes time, effort and attention from subjects. As a result of the study subjects can be advised towards the use of a directional microphone setting to improve their speech recognition performance in noise.
- Main changes (audit trail)7-jan-2016: Amendement:

Intervention:During two test session subjects are provided with the latest speech processor for the CI ear and a state-of-the-art hearing aid in the other ear allowing different microphone configurations: standard omnidirectional processing, directional multi-microphone processing and binaural beamforming.

Primary outcome:The primary outcome is the effect of microphone configuration on speech recognition performance in noise. Hereby two main effects are distinguished:
- Directional effect, defined as the difference between the standard omnidirectional configuration, and the directional multi-microphone system in both CI and HA.
- Asymmetric effect, defined as the difference between a symmetric (directional multi-microphone system in both CI and HA) and an asymmetric directional configuration (standard omnidirectional microphone in HA and directional multi-microphone system in CI).
With the amendment “Binaural Beam” the following primary study parameters were added:
- Symmetric binaural directional benefit, defined as the difference between the omnidirectional configuration and the binaural beamforming system when listening with both CI and HA.
- Asymmetric binaural directional benefit, defined as the difference between the omnidirectional configuration and the binaural beamforming system when listening with CI alone.

Secondary outcome: Secondary outcomes in this study are: - Effect of masker type, defined as the performance difference between a stationary speech-shaped background noise and a fluctuating competing talker.
- Listening effort, defined as the effort it takes to listen to speech in noise in the different directional and masking conditions.
With the amendment “Binaural Beam” the following primary study parameters were added:
- Omnidirectional bimodal benefit, defined as the difference between hearing with both CI and HA in the omnidirectional mode compared to listening with only a CI in omnidirectional mode.
- Binaural directional bimodal benefit, defined as the difference between hearing with both CI and HA when binaural beamforming is activated compared to listening with only a CI when binaural beamforming is activated.

23-aug-2016:

Inclusion NEW:
Bimodal Group:
1. capacitated adult (>18 years of age)
2. patient of CI-team South-East Netherlands
3. user of a unilateral cochlear implant (CI) of the brand

Advanced Bionics (AB)
4. first fit CI >= 6 months ago
5. wearing CI speech processor (almost) always (i.e. circa 10 hours a day)
6. wearing a contralateral hearing aid >50% of the time (i.e. circa 5 hours a day)
7. able to perform the speech-in- noise test (i.e. speech recognition in quiet >50%)
8. willing and able to visit hospital and participate in testing
9. agreed to participate in this study (by informed consent)

Bilateral group:

1. capacitated adult (>18 years of age)
2. patient of CI-team azM, RadboudUMC or UMCU
3. Former subject in the study NL24660.018.08/NTR1722 who completed the full fuollow-up period of four years since first implantation
4. user of a bilateral cochlear implants (CI’s) of the brand Advanced Bionics (AB)
5. first fit of second CI >= 6 months ago
6. wearing CI speech processor in both ears (almost) always (i.e. circa 10 hours a day)
7. able to perform the speech-in- noise test (i.e. speech recognition in quiet >50%)
8. willing and able to visit hospital and participate in testing
9. agreed to participate in this study (by informed consent)

And additionally in case of patient Radboud UMC or UMCU:
1. Agreed to let research team inform own CI-team of participation in current study (by informed consent)
2. Agreed to let research team retrieve basic audiological information from own CI-team (by informed consent)

Exclusion criteria NEW:
Bimodal group:
1. non fluent in Dutch
2.<18 years of age or incapacitated
3. bilateral cochlear implant user (CI+CI)

Bilateral group:
1. non fluent in Dutch
2. <18 years of age or incapacitated

Target number of participants: 12 bimodal + 12 bilateral

Intervention NEW:
During two test session bimodal subjects are provided with the latest speech processor for the CI ear and a state-of- the- art hearing aid in the other ear. The bilateral group will be provided with the latest CI speech processor in both ears during a single test session. Both CI and HA devices allow different microphone configurations: standard omnidirectional processing and directional multi- microphone processing in each ear separately (monaural) or combined cross ears (binaural).

Primary outcome NEW:
The primary outcome is the effect of microphone configuration on speech recognition performance in noise. Two directional microphone systems will be addressed, a monaural and a binaural system, and compared to the standard omnidirectional microphone setting. The microphone systems will be tested in a symmetric configuration (same setting across ears) and/or asymmetric configuration (different setting across ears).

Secondary outcome NEW:
Aside from the primary outcome also listening effort, defined as the effort it takes to listen to speech in noise, will be tested. Furthermore the degree of bimodal benefit will be addressed as well as the effect of noise type, stationary versus fluctuating. Results between the two patient groups, bimodal versus bilateral, will be compared.
- RECORD13-nov-2014 - 23-aug-2016


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