Gantz Bruce J, Turner Christopher W
Department of Otolaryngology-Head and Neck Surgery, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, 21201 PFP, Iowa City IA 52242-1078, USA.
Laryngoscope. 2003 Oct;113(10):1726-30. doi: 10.1097/00005537-200310000-00012.
OBJECTIVES/HYPOTHESIS: The concept of combining electrical stimulation for high-frequency sound with acoustic hearing for low-frequency information was tested. In addition, whether residual hearing can be preserved when an electrode is placed into the inner ear up to 10 mm and whether place of electrical stimulation influences speech perception were tested.
A single-subject clinical trial design was employed.
Six postlingual adults with severe high-frequency hearing impairment were recruited to participate in the study. A new six-channel cochlear implant was designed for the clinical trial. The intracochlear electrodes were either 6 or 10 mm in length based on a Nucleus CI-24 multichannel implant. Monosyllabic word understanding and consonant identification testing in a recorded sound-only condition were used to assess changes in speech perception. Follow-up was greater than 12 months.
Acoustic hearing was preserved in all six subjects (n = 3, 6-mm electrodes; n = 3, 10-mm electrodes). Preoperative monosyllabic word and sentence scores were unchanged in all subjects following implantation. A 30% to 40% improvement in consonant recognition occurred with the 10-mm electrode. The subjects with 10-mm electrodes were able to understand 83% to 90% of the monosyllabic words using the implant plus binaural hearing aids. Scores were more than doubled when compared with preoperative scores with hearing aids only.
The human ear has the capability to integrate both acoustic and high-frequency electrically processed speech information. Placement of a short, 10-mm electrode does not appear to damage residual low-frequency inner ear hair cell function, interfere with the micro mechanics of normal cochlear vibration, or decrease residual speech perception. The improvement in speech recognition was due primarily to the increased perception of higher-frequency consonantal speech cues, and this improvement took several months to become apparent. Such a device can provide a substantial benefit in speech understanding to individuals with severe high-frequency hearing loss, while still maintaining the benefits of the residual lower-frequency acoustic hearing. The position of the electrode and the place of frequency information within the cochlea were shown to be important factors in the success of such a device.
目的/假设：测试了将高频声音的电刺激与低频信息的声学听力相结合的概念。此外，还测试了将电极插入内耳达10毫米时残余听力是否能够保留，以及电刺激部位是否会影响言语感知。
采用单受试者临床试验设计。
招募了6名严重高频听力受损的语后聋成年人参与研究。为该临床试验设计了一种新型六通道人工耳蜗。基于Nucleus CI - 24多通道植入物，耳蜗内电极长度为6毫米或10毫米。在仅记录声音的条件下进行单音节词理解和辅音识别测试，以评估言语感知的变化。随访时间超过12个月。
所有6名受试者（n = 3，6毫米电极；n = 3，10毫米电极）的声学听力均得以保留。植入后所有受试者术前单音节词和句子得分均未改变。使用10毫米电极时，辅音识别提高了30%至40%。使用10毫米电极的受试者使用人工耳蜗加双耳助听器能够理解83%至90%的单音节词。与仅使用助听器的术前得分相比，得分增加了一倍多。
人类耳朵有能力整合声学和高频电处理的言语信息。植入10毫米的短电极似乎不会损害残余的低频内耳毛细胞功能，不会干扰正常耳蜗振动的微力学，也不会降低残余言语感知。言语识别的改善主要归因于对高频辅音言语线索感知的增加，且这种改善需要数月时间才会明显显现。这样一种装置可以为严重高频听力损失的个体在言语理解方面带来显著益处，同时仍保留残余低频声学听力的益处。电极位置和耳蜗内频率信息的部位被证明是这种装置成功的重要因素。
