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Biomedical subjects

W H Shapiro

Publications and source records attributed to W H Shapiro.

9 recordsLinked to original sources

Use of a multichannel cochlear implant in the congenitally and prelingually deaf population.

Fourteen children and three adults, each congenitally and prelinguistically deaf, received the Nucleus multichannel implant. All underwent extensive evaluations and rehabilitation. The surgery was uneventful, and no patients have been lost to follow-up. Results have shown a significant increase in auditory and speech reception and perception skills in all children. Some children have open-set speech recognition using the prosthesis alone. The adults have shown an increased awareness of sound along with minimal improvement in perceptual skills. This supports the concept that early implantation of congenitally and prelinguistically deaf individuals results in improved performance.

Adult

Sensory aids in conjunction with cochlear implants.

The use of cochlear implants in profoundly hearing-impaired individuals can restore varying degrees of auditory capabilities. Although very little auditory information is transmitted to these patients through amplification systems, we hypothesized that some of the cues obtained from sensory aids might be helpful when used in conjunction with the cochlear implant postoperatively. Eight patients implanted at NYU Medical Center, Bellevue Hospital Center, have used some sensory aid in addition to the Nucleus multichannel cochlear prosthesis. All subjects were evaluated using standard auditory tests including pure-tone and speech audiometry, portions of the Minimal Auditory Capabilities (MAC), Speech Pattern Contrast Perception (SPAC), Iowa test batteries; and the Early Speech Perception (ESP), Word Intelligibility by Picture Identification (WIPI), and Glendonald Auditory Screening Procedure (GASP), where appropriate. Subjects were evaluated under three conditions: implant alone, implant plus sensory aid, and sensory aid alone. Results indicate that the interaction between a multichannel cochlear implant and a sensory aid can provide some improved performance for adult implanted patients (i.e., they do better under the dual condition than in the implant-alone condition). Variables such as thresholds in the nonimplanted ear and usage time can affect the outcome.

Adult

Effects of chronic electrical stimulation on patients using a cochlear prosthesis.

Eighteen patients using the Nucleus multichannel cochlear prosthesis underwent annual evaluations for electrical thresholds, dynamic range, and speech recognition abilities for a period of 1 to 5 years. Results revealed no correlation between length of usage of a cochlear implant and electrical thresholds. The dynamic range was initially wider in the patients with open-set speech recognition, but narrowed in subsequent years. There was a correlation between length of deafness and postoperative performance.

Auditory Threshold

The prognostic value of round window electrical stimulation in cochlear implant patients.

The use of preoperative round window stimulation has been advocated for its possible predictive value in cochlear implant patients. We have attempted to correlate cause of deafness, preoperative radiologic study, and postoperative stimulability and performance with preoperative stimulation. Round window stimulation procedures consisted of measurements of electrical thresholds and comfort levels, gap detection, and temporal difference limen. Radiologic studies were performed using high-resolution computerized semi-axial and coronal tomography with 1.5-millimeter overlapping cuts. Patient performance was measured using a standard audiologic test battery. Sixteen postlingually, profoundly deaf adults who received the Nucleus multichannel cochlear implant were studied. All 16 patients who responded to preoperative stimulation had acceptable CT scans for the ear operated on and stimulated postoperatively with the prosthesis. The lowest level at which a patient could reliably detect a gap between two signals ranged from 10 to 150 milliseconds, which was not predictive. For the temporal difference limen task, the patients who could reliably identify the longer of two pulses when the difference was less than 100 milliseconds did achieve varying amounts of open-set speech discrimination postoperatively. In summary, results indicate that the preoperative psychoacoustic electrical stimulation test battery provides useful information in predicting postoperative performance.

Cochlea

Telephone speech comprehension with use of the nucleus cochlear implant.

The reported telephone usage by cochlear implant recipients has become a major issue of controversy. Although patients and clinicians report good communication skills via the telephone, no standardized tests have been used and no quantifiable results have been reported. In an effort to determine the extent to which our better-performing patients can use the telephone, we established a clinical protocol to assess their ability to recognize speech, taking into consideration the problems inherent in telephone testing. Eight cochlear implant recipients were administered the NU-6 Monosyllabic Word Test and the City University of New York Topic Related Sentences under the following listening conditions: soundfield in a soundproof suite and via telephone within the hospital, locally, and long-distance. Twenty-three percent of the patients implanted at New York University Medical Center demonstrated a significant degree of telephone communication ability.

Cochlear Implants

Long-term effects of multichannel cochlear implant usage.

A major concern regarding multichannel (multi-electrode) cochlear prosthesis usage has been the possibility of long-term deleterious physiological effects such as the degeneration of spiral ganglion cells, neuronal degeneration, and new bone formation. These effects, if present, would become evident in the deterioration of hearing sensation and performance of the cochlear implant recipient on a battery of audiologic tests. To date, five patients using the Australian multi-electrode multichannel cochlear implant have undergone a 1-year evaluation of the device. The assessment includes a check of electrical threshold and comfort levels for each electrode, sound field pure tone and speech thresholds, the MAC battery, vowel and consonant recognition tests, and speech tracking tasks. All results were compared to those obtained postoperatively following stimulation and a 3-month training period. Results to date have shown no deterioration in implant functioning in all patients tested. Periodic extensive monitoring of all implant recipients is advocated in order to evaluate the possibility of long-term effects.

Audiometry, Pure-Tone

Evaluation of a cochlear prosthesis using connected discourse tracking.

A multichannel cochlear prosthesis was evaluated using the method of Connected Discourse Tracking. Data were obtained from five subjects over a 10-week period. Significant learning effects were obtained both with and without the prosthesis. The method of orthogonal polynomials was used to obtain a statistically precise fit for each learning curve. The curves differed both in terms of shape and average rate of learning. The two best subjects showed substantial improvements, reaching tracking rates in excess of 90 words-per-minute. A method for representing prosthesis-based improvements, which takes learning effects into account, is developed and discussed.

Analysis of Variance

Clinical trials with a 22-channel cochlear prosthesis.

During 1984, six patients have been implanted with a 22-channel cochlear prosthesis. The device features a programmable wearable speech processor using a speech feature encoding strategy. A strict clinical protocol was followed, and no patients have been lost to follow-up. All patients are regular users of the device and have shown a restoration of hearing sensation in response to acoustic stimuli. Pure tone averages ranged from 20 to 47 dB HL and speech detection thresholds varied from 15 to 32.5 dB HL. All patients have shown a recognition of a large variety of environmental sounds, and an improvement in speech recognition ability when the device is used in conjunction with lipreading. Speech reception thresholds using spondee words without lipreading were obtained in three patients at levels of 27.5 to 55 dB HL and one patient had an open-set speech discrimination score (w-22 word list) of 42% without lipreading. In addition, two of the patients show an ability to have limited interactive conversation without the use of lipreading.

Adult