Hearing Loss, Cochlear
Conditions
Keywords
Iteraural Time Difference
Brief summary
The aim of the study is to evaluate the interaural time difference (ITD) benefit in patients with bilateral cochlear implants and to assess speech performance in noisy conditions compared to normal hearing listeners. Half of participants are bilateral cochlear implants users, while the other are normal hearing listeners.
Detailed description
Listening in noisy environments is part of everyday life, it is based on binaural phenomena such as spatial localization.
Interventions
OTHERS0N0
(no ITD)
OTHERS0N500
(ITD +500µs on noise)
OTHERS-500N500
(ITD -500µs on signal and +500 µs on noise)
OTHERS0N1000
(ITD + 1000 µs on noise)
OTHERS0Nuncorr
(no ITD cue, with uncorrelated stimulation frame)
Sponsors
Oticon Medical
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Fluent in local language * Normal hearing listener: * pure tone threshold \> 25dB from 125Hz to 12kHz * Cochlear implant recipient * bilaterally implanted 6 months at least, the second implant should be implanted 6 months at least before participant inclusion * Digisonic SP® cochlear implants user
Exclusion criteria
* binaural sensitivity threshold \< 1000µs
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| speech reception threshold (SRT) in bilateral cochlear implant user with ITD cue | day 0 | SRT is used as an outcome measure to quantify the acuity for speech perception in noise with Interaural Time Difference between the two ears. Signal recognition in a background noise is assessed the following conditions S0N0, S0N500, S0N1000, S-500N500 et S0Nuncorr. The noise level is constant at 65 dB SPL, the signal level is modified in the adaptive procedure in order to converge towards a score of 50% of correct response. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| speech reception threshold (SRT) in bilateral cochlear implant user without ITD cue and in normal hearing listeners | day 0 | SRT is used as an outcome measure to quantify the acuity for speech perception in noise without Interaural Time Difference between the two ears. |
| ITD sensitivity in bilateral cochlear implant user | day 0 | Speech signal and noise are presented at 65dB SPL. Participant adjusts the Interaural Time Difference between the speech signal and noise between -1000 and +1000µs. Participant moves the cursor on the interface until he/she hears a difference in sound. |
| Preferred jitter in bilateral cochlear implant user | day 0 | Speech signal and noise are presented at 65dB SPL. Participant adjusts the jitter of the train pulse timing from 0 to +1000µs to improve the Interaural Time Difference. |
Outcome results
None listed