Bilateral cochlear implants in children: localization acuity measured with minimum audible angle

Area of Science:

• Audiology
• Neuroscience
• Speech and Hearing Sciences

Background:

• Bilateral cochlear implantation (BI) in children involves sequential procedures, leading to varied auditory experience between ears.
• Assessing sound localization acuity is crucial for auditory development and spatial awareness in children with hearing impairments.

Purpose of the Study:

• To evaluate sound localization in children with sequential BI cochlear implants.
• To determine the impact of BI auditory experience on sound localization.
• To investigate the benefit of a hearing aid in the non-implanted ear for sound localization.

Main Methods:

• Two groups of children were studied: 13 with BI cochlear implants and 6 with a cochlear implant plus a hearing aid.
• Minimum audible angle thresholds were measured using computerized interactive software in sound-treated booths.
• Testing was conducted in bilateral and monaural listening conditions.

Main Results:

• Approximately 70% of children with BI cochlear implants discriminated sound sources at separations of 20 degrees or less.
• Children with BI cochlear implants performed better bilaterally than with a single implant.
• Performance was generally better with the first cochlear implant than the second, suggesting improvement with auditory experience.

Conclusions:

• Many children with sequential BI cochlear implants demonstrate enhanced sound localization with two implants compared to one.
• Bilateral cochlear implants generally yield better sound localization outcomes than a cochlear implant combined with a hearing aid.
• Further research with larger populations is needed to fully understand the long-term benefits and contributing factors for BI cochlear implant use.