Effects of Electrode Insertion Depth on Mandarin Speech Understanding Using Combined Electric and Acoustic Stimulation

Experiments based on combined electric andacoustic stimulation (EAS) had acquired a good recovery effecton English-speaking patients with moderate to severehigh-frequency hearing loss. This paper focused on the effect ofthe electrode insertion depth on Mandarin speechunderstanding when using EAS. Through acoustic simulationexperiments in large amount of Mandarin material generatedby EAS simulation model, we assessed the recognitionaccuracy in vowels, consonants, numbers, tones and singlewords, and discussed the effect of the electrode insertion depth.The recognition scores of all kinds of materials droppedrespectively with the decreasing insertion depth, whichsuggested that electrodes as long as possible for specificpatients were preferable to recover their speech recognition.However, long electrodes increase the risk of damagingresidual low-frequency hearing. Therapist should strike abalance between recovery effect and risks.