Role of a Multichannel Electrotactile Speech Processor in a Cochlear Implant Program for Profoundly Hearing-impaired Adults*

Abstract

Four profoundly hearing-impaired adults who did not meet current selection criteria for implantation at the University of Melbourne were each fitted with a wearable multichannel electrotactile speech processor (Tickle Talker). The subjects were evaluated with a test battery of speech discrimination tests subsequent to training in use of the device. Thresholds for detection of pure tones were lower for the Tickle Talker than for hearing aids across the frequency range 250 to 4000 Hz. Mean speech detection thresholds for the Ling 5-sound test showed that all sounds were detected by users of the electrotactile device at normal conversational speech intensity levels. Mean speech discrimination scores were significantly higher (p c 0.05) in the tactually aided condition as compared with the tactually unaided for identification of vowels and consonants, on open-set words, open-set sentences, and on connected discourse tracking. Mean scores increased by 20% for vowels, 19% for consonants, 30% for openset words, and 25% for open-set sentences when the Tickle Talker was used in a multimodal combination with lipreading or lipreading and hearing aids. Speechtracking rates for three subjects showed increases of from 18 to 28 wpm when the tactile device was used. Comparison of tactually aided versus unaided tracking rates for two subjects with long-term experience shows continuing improvement with additional experience with the device. These results demonstrate that hearing-impaired adults not meeting selection criteria for cochlear implantation may benefit from use of an electrotactile speech processor, and highlight the potential benefits from integration of such devices into cochlear implant programs for profoundly hearing-impaired patients. (Ear Hear 12 1:39-46)

Electro-Tactile Stimulation Enhances Cochlear Implant Speech Recognition in Noise

“…In order to provide full-spectrum information for speech recognition, previous tactile aids had over-ambitious goals 41 with designs having multiple contacts and complex stimulation patterns 42 . In contrast, the present ETS results suggest that tactile aids should be designed with different goals when integrated with cochlear implants.…”

Factors in the Development of a Training Program for Use with Tactile Devices

“…The results of suggested that 70 hr of training provided to normally hearing subjects was insufficient to maximize device benefits in open-set word recognition. Further studies showed that the benefits of tactually encoded speech feature information for connected discourse tracking continued to increase for two hearingimpaired subjects over 28 and 43 weekly sessions, respectively, and that no plateau in improvement was noted (Cowan et al, 1991).…”

“…The performance and consistency of device use (for hearing aids, cochlear implants, and tactile devices) by children may be affected by other factors such as motivation, peer pressure and reinforcement by teachers and parents. The attitude toward tactile device use shown by the professionals and other adults involved with the child's training program is a significant factor, which may vary in importance for any particular child (Galvin, Cowan, Sarant, Alcintara, Blarney, & Clark, 1991). It is important that parents and teachers understand the use of and potential benefits available from a specific tactile device, and that they provide positive support for the child.…”

Articulation Accuracy of Children Using an Electrotactile Speech Processor

“…The speech perception and psychophysical experiments conducted with the Tickle Talker clearly show that the device provides substantial speech feature information (Blarney & Clark, 1987;Cowan et al, 1990Cowan et al, , 1991. However, the extent to which individual users have utilized this information has varied.…”