Biomedical subjects

S B Waltzman

Publications and source records attributed to S B Waltzman.

13 recordsLinked to original sources

PubMed1992

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↗

PubMed1992

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↗

PubMed1991

Prospective randomized clinical trial of advanced cochlear implants: preliminary results of a Department of Veterans Affairs Cooperative Study.

This study is a randomized clinical trial to compare the efficacy and safety of one single-channel implant (the 3M/Vienna intracochlear device) and two multichannel cochlear implants (the Nucleus 22-channel device and the Smith & Nephew Richards Ineraid device). Seven Veterans Administration centers are participating in the study. The patient population consists of 82 veterans with postlingual, bilateral profound sensorineural hearing losses who obtain no benefit from amplification. All potential subjects were screened with a battery of audiologic tests. The three device groups are balanced on baseline patient characteristics. One month after operation, the devices were stimulated and programmed and the patients evaluated. Follow-up evaluations were completed at 3 and 12 months poststimulation and then annually until the end of the study. The 12-month data indicate that performance with the multichannel devices is superior to that with the single-channel device.

Adult↗

PubMed1991

Facial nerve stimulation with cochlear implantation. VA Cooperative Study Group on Cochlear Implantation.

The course of the facial nerve may place it within the current field generated by an activated cochlear implant to produce incidental facial movement. We investigated the presence of facial nerve stimulation associated with cochlear implants in the VA Cooperative Study of Advanced Cochlear implants. Twelve of 82 patients enrolled in this study demonstrated facial nerve stimulation within 2 years of implant activation. Facial nerve stimulation in six patients with multiple channel implants (Nucleus or ineraid devices) either resolved spontaneously (n = 2), or was eliminated by deactivating basal (n = 2) or apical (n = 2) electrodes. Two of six patients with single-channel electrodes (3-M/Vienna devices) demonstrated facial nerve stimulation that resolved spontaneously (n = 2), resolved with lowering current output (n = 2), or was refractory to processor adjustment (n = 2). Intraoperative assessment in one of the refractory cases indicated that facial nerve stimulation resulted from current spread through the modiolus to activate the facial nerve. A variety of factors, including implant design, stimulus parameters, and local tissue impedances, may interact to produce incidental facial stimulation. Low-impedance pathways between the scala tympani and the modiolus may deserve increased recognition as an interactive factor in cochlear implant performance.

Adult↗

PubMed1991

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↗

PubMed1990

Performance of cochlear implant patients as a function of time.

The speech perception abilities of 15 patients were measured preoperatively using hearing aids and postoperatively using the Nucleus 22-channel cochlear implant over a period of 1, 2, or 3 years. Analysis of mean data revealed that, although the greatest amount of improvement in speech perception scores occurred between the preoperative and 3-month poststimulation evaluation, there was also significant improvement in perception of segmental features and open-set speech recognition over the 3-year time period. When individual patient data were examined, however, it was clear that these improvements were due, in large part, to the performance of a subset of patients who had measurable open-set speech recognition abilities at the time of their 3-month, poststimulation evaluation. Subjects who used the processing scheme that included coding of F1 showed significantly more improvement over time than subjects who used the original F0F2 processing scheme exclusively. It was concluded that open-set speech recognition ability at 3 months is an important prognostic indicator of continued improvement in speech perception abilities over time.

Adult↗

PubMed1990

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↗

PubMed1989

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↗

PubMed1986

Acoustic neuroma presenting as sudden hearing loss with recovery.

In our series of patients operated on for acoustic neuromas at New York University Medical Center between 1974 and 1983, 13% (17 of 133) had sudden hearing loss. Of these, approximately 23% (four of 17) had recovered auditory function before acoustic neuroma extirpation. Three patients spontaneously recovered, while one improved with steroid therapy. Contrast computerized tomography demonstrated a widened internal auditory canal and evidence of cerebellopontine angle tumor, respectively, in 88% and 59% of patients with sudden hearing loss and acoustic neuroma. Clinical characteristics suggesting acoustic neuroma as the cause of sudden hearing loss with or without auditory recovery could not be identified in our series. Our data support the rationale that patients with unilateral sudden hearing loss, even with recovery, must be evaluated for a possible cerebellopontine lesion.

Adolescent↗

PubMed1986

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↗

PubMed1986

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↗

PubMed1985

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↗

PubMed1978

Backward and forward masking with reproducible noise bursts.

This study investigated the effects of two "frozen" narrow-band waveforms with different waveform envelopes 50 msec in duration and centered at 250 Hz, on temporal masking at short masking intervals and, further, assessed the effects of phase shifts on backward and forward masking. Four normal-hearing experienced Ss detected a monaurally presented 250-Hz tone burst, 12 msec in duration, that either preceded, occurred simultaneously with, or followed a burst of the narrow-band noise. A 2IFC technique was used with a transformed up-down procedure for threshold estimation. The masking intervals from onset of masker to onset of tonal pulse ranged from -30 to +70 msec. The 3 phasic conditions for the signal were in-phase, 90 degrees out-of-phase, and 180 degrees out-of-phase. Results of this experiment substantiated the data of other researchers who have shown greater backward than forward masking at short masking intervals and greater masking was found for all simultaneous conditions than for any of the backward or forward masking conditions. In addition, differences between the two noise waveforms, as well as the phase shifts, had a significant effect on the thresholds obtained for the backward and forward masking conditions, as well as for the simultaneous masking conditions. Criterion change and waveform storage are discussed as possibly having an effect up these variables.

Acoustic Stimulation↗