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Sound localization with bilateral cochlear implants in noise: how much do head movements contribute to localization?
Cochlear Implants International
|May 21, 2013
Summary
Bilateral cochlear implant (CI) users struggle with sound localization. While head movements helped reduce front-back errors for longer sounds, overall accuracy did not improve, and CI users had difficulty targeting sound sources.
Area of Science:
- Audiology
- Neuroscience
- Biomedical Engineering
Background:
- Bilateral cochlear implant (CI) users exhibit significant sound source localization deficits compared to normal hearing (NH) individuals.
- These deficits are exacerbated by background noise and reverberation, leading to directional errors and front-back confusions.
Purpose of the Study:
- To investigate the efficacy of head movements in improving sound source localization for bilateral CI users.
- To compare the sound localization strategies of CI users and NH listeners.
Main Methods:
- Speech sentences of varying durations (0.5, 2, 4.5 seconds) were presented in noise to bilateral CI users and NH listeners.
- Sound localization was assessed with and without the ability to perform head movements.
- Head movement trajectories were analyzed to evaluate targeting accuracy.
Main Results:
- Bilateral CI users significantly reduced front-back confusions with head movements for middle and long signal durations.
- Angular accuracy in sound source localization did not improve with head movements for CI users.
- NH listeners accurately targeted sound sources with head movements, while CI users showed difficulties.
Conclusions:
- Head movements can partially mitigate specific localization errors (front-back confusion) in bilateral CI users.
- The ability to improve overall localization accuracy and target sound sources effectively remains a challenge for CI users.
- Further research is needed to enhance spatial hearing abilities in individuals with bilateral cochlear implants.
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