[A long term effect on speech recognition in the patients with simultaneous bilateral cochlear implants].

Area of Science:

• Audiology and Otolaryngology
• Biomedical Engineering
• Neuroscience

Background:

• Cochlear implants (CI) are crucial for restoring hearing in individuals with severe to profound hearing loss.
• The efficacy of bilateral cochlear implantation compared to unilateral implantation, particularly regarding speech recognition in complex auditory environments, requires further investigation.

Purpose of the Study:

• To evaluate the impact of simultaneous bilateral cochlear implantation (CI) on hearing thresholds and speech recognition in quiet and noisy environments.
• To compare the performance of individuals with bilateral CI against those with unilateral CI, considering factors like age, gender, and duration of deafness.

Main Methods:

• A comparative study involving nine subjects with simultaneous bilateral CI and nine with unilateral CI.
• Assessment of hearing thresholds and speech recognition (phrases, disyllabic words, single words) in quiet and noise.
• Simulation of binaural hearing effects (head shadow, redundancy, squelch) under varying signal-to-noise ratios (SNR) in noise environments.

Main Results:

• Bilateral CI significantly reduced hearing thresholds compared to unilateral CI (P<0.05).
• Speech recognition in quiet showed no significant difference between groups (P>0.05).
• In noise, bilateral CI demonstrated significantly better speech recognition, particularly in head shadow, binaural redundancy, and binaural squelch conditions (P<0.01).

Conclusions:

• Simultaneous bilateral cochlear implantation effectively lowers hearing thresholds.
• Bilateral CI significantly enhances speech recognition capabilities, especially in noisy environments, by leveraging binaural hearing benefits.
• The findings support bilateral CI as a superior option for improving auditory function in challenging listening situations.