Objective: To investigate the speech discrimination abilities of patients with bilateral cochlear implants.
Methods: The speech discrimination scores of Cantonese lexical tones were compared between two patients with unilateral and bilateral cochlear implants at different signal to noise (S/N) ratios.
Results: At favorable listening conditions with S/N ratios of +15, +10, and the mean binaural speech discrimination scores were 96%, 92% and 88%, but the mean monaural speech discrimination scores from the left and right ear were 86%, 83% and 74% respectively. At unfavorable listening conditions with adverse S/N ratios of 0, -5, -10 and -15, almost no speech discrimination scores could be obtained from monaural hearing but 80%, 72%, 68% and 54% respectively from binaural stimulation.
Conclusion: Bilateral cochlear implants improve the discrimination of Cantonese lexical tones better than unilateral cochlear implant at various S/N ratios This study confirms the benefits of binaural hearing even in patients using bilateral cochlear implants.