Evaluate the performance of directional microphone systems in binaural (bimodal or bilateral) cochlear implant users
ID
Source
Brief title
Condition
- Hearing disorders
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The primary outcome is the effect of microphone configuration on speech
recognition performance in noise. Two main effects are distinguished:
- Symmetric directional benefit, 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.
With the amendment "Bilateral Zoom" the following primary study parameters were
added:
- Bilateral monaural directional benefit, defined as the difference between the
standard omnidirectional configuration and the monaural beamforming system when
listening with two CI*s.
- Bilateral binaural directional benefit, defined as the difference between the
standard omnidirectional configuration (test condition 1) and the binaural
beamforming system (test condition 3) when listening with two CI*s.
Secondary outcome
Secondary outcomes in this study are:
- Asymmetric directional benefit, defined as the difference between the
standard omnidirectional configuration in both CI and HA, and an asymmetric
directional configuration (standard omnidirectional microphone in HA and
directional multi-microphone system in CI).
- 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 secondary 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.
With the amendment "Bilateral Zoom" the following secondary study parameter was
added:
- Bilateral pinna effect, defined as the difference between the pure
omnidirectional configuration and the pinna located standard omnidirectional
configuration when listening with two CI*s.
Background summary
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.
Study objective
Evaluate the performance of directional microphone systems in binaural (bimodal
or bilateral) cochlear implant users
Study design
A cross-over repeated measures design is carried out to single-blind evaluate
the performance of directional microphone systems. For each directional
setting, speech recognition performance in noise and listening effort are
assessed using two different masking materials (stationary noise versus
fluctuating talker).
Intervention
During a test session subjects are provided with the latest speech processor
for the CI and when applicable a state-of-the-art hearing aid allowing
different microphone configurations: standard omnidirectional processing versus
directional multi-microphone processing.
Study burden and risks
Study associated health risks are thought of as non-existent since this is a
study with no invasive interventions. The topic under investigation is the
effect of different directional microphone systems. This is a pre-processing
feature of hearing devices that are currently available on the market
(CE-marked) and are commonly used in current CI and HA patients. All products
will be used within their indication in normal clinical hearing rehabilitation
and not in combination with other products.
Only the software used for CI-fitting in bimodal session 2 does not have a
CE-marking. The risk of using this software however are considered to be
non-significant (see IMDD in section D of the research dossier).
Despite the low risks, participation however takes time and effort from
subjects: two test sessions of approximately 3 hours for the bimodal group and
a single test session of approximately 3 hours, for the bilateral group.
P. Debyelaan 25
Maastricht 6229 HX
NL
P. Debyelaan 25
Maastricht 6229 HX
NL
Listed location countries
Age
Inclusion criteria
Bimodal group:
In order to be eligible to participate in the bimodal group of this study, a subject must meet all of the following criteria:
* capacitated adult (>18 years of age)
* patient of CI-team South-East Netherlands
* user of a unilateral cochlear implant (CI) of the brand Advanced Bionics (AB)
* first fit CI ><= 6 months ago
* wearing CI speech processor (almost) always (i.e. circa 10 hours a day)
* wearing a contralateral hearing aid >50% of the time (i.e. circa 5 hours a day)
* able to perform the speech-in-noise test (i.e. speech recognition in quiet >50%)
* willing and able to visit the azM and participate in testing
* agreed to participate in this study (by informed consent);Bilateral group:
In order to be eligible to participate in the bilateral group of this study, a subject must meet all of the following criteria:
* Capacitated adult (>18 years of age)
* Patient of CI-team azM, RadboudUMC or UMCU
* Former subject in the study *Bilateral Cochlear Implantation Benefits in Adult Users of the HiRes(R)
* 90K Bionic Ear System* (NL24660.018.08/NTR1722) who completed the full follow-up period of four years since the first implantation
* User of bilateral cochlear implants (CI*s) of the brand Advanced Bionics (AB)
* First fit of second CI *<= 6 months ago
* Wearing CI speech processor in both ears (almost) always (i.e. circa 10 hours a day)
* Able to perform speech-in-noise test (i.e. speech recognition in quiet with bilateral CI >50%)
* Willing and able to visit the azM and participate in testing
* Agreed to participate in this study (by informed consent);And additionally in the case of a patient of CI-team UMCU or RadboudUMC:
* Agreed to let the research team of the current study inform the own CI-team respectively of his/her participation in the current study (by informed consent)
* Agreed to let the research team of the current study retrieve his/her basic audiological information from the CI-team UMCU or RadboudUMC (by informed consent)
Exclusion criteria
Bimodal group:
A potential subject who meets any of the following criteria will be excluded from participation in the bimodal group:
* non fluent in Dutch
* < 18 years of age or incapacitated
* bilateral cochlear implant user (CI+CI) ;Bilateral group:
A potential subject who meets any of the following criteria will be excluded from participation in the bilateral group:
* non fluent in Dutch
* < 18 years of age or incapacitated
Design
Recruitment
Medical products/devices used
Followed up by the following (possibly more current) registration
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In other registers
| Register | ID |
|---|---|
| CCMO | NL51559.068.14 |