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Biomedical subjects

S A Hellman

Publications and source records attributed to S A Hellman.

9 recordsLinked to original sources
PubMed1992

Auditory perception changes after reimplantation in a child cochlear implant user.

The ability to remove cochlear implants from children and subsequently reimplant a more complex device in the same ear was the concern of this single case study. A postlinguistically deafened child, J.L., received a single-channel cochlear implant 1 yr after contracting meningitis and suffering a profound bilateral sensorineural hearing loss. After 3 yr of successful implant use, J.L. suffered an internal coil failure. She was then explanted and reimplanted with a multichannel cochlear implant in the same ear. This case report details her speech perception skills with her single-channel cochlear implant, a vibrotactile aid, and a multichannel cochlear implant. Results from auditory perceptual measures suggest that the explantation/reimplantation process was technically feasible with no adverse effects on J.L.'s ability to utilize a more sophisticated device and to exceed her previous performance levels.

Acoustic Stimulation↗
PubMed1992

Vowel perception strategies of normal-hearing subjects and patients using Nucleus multichannel and 3M/House cochlear implants.

Vowel perception strategies were assessed for two "average" and one "star" single-channel 3M/House and three "average" and one "star" Nucleus 22-channel cochlear implant patients and six normal-hearing control subjects. All subjects were tested by computer with real and synthetic speech versions of [symbol: see text], presented randomly. Duration, fundamental frequency, and first, second, and third formant frequency cues to the vowels were the vowels were systematically manipulated. Results showed high accuracy for the normal-hearing subjects in all conditions but that of the first formant alone. "Average" single-channel patients classified only real speech [hVd] syllables differently from synthetic steady state syllables. The "star" single-channel patient identified the vowels at much better than chance levels, with a results pattern suggesting effective use of first formant and duration information. Both "star" and "average" Nucleus users showed similar response patterns, performing better than chance in most conditions, and identifying the vowels using duration and some frequency information from all three formants.

Adolescent↗
PubMed1992

Speech changes following reimplantation from a single-channel to a multichannel cochlear implant.

The speech of a postlingually deafened preadolescent was recorded and analyzed while a single-electrode cochlear implant (3M/House) was in operation, on two occasions after it failed (1 day and 18 days) and on three occasions after stimulation of a multichannel cochlear implant (Nucleus 22) (1 day, 6 months, and 1 year). Listeners judged 3M/House tokens to be the most normal until the subject had one year's experience with the Nucleus device. Spectrograms showed less aspiration, better formant definition and longer final frication and closure duration post-Nucleus stimulation (6 MO. NUCLEUS and 1 YEAR NUCLEUS) relative to the 3M/House and no auditory feedback conditions. Acoustic measurements after loss of auditory feedback (1 DAY FAIL and 18 DAYS FAIL) indicated a constriction of vowel space. Appropriately higher fundamental frequency for stressed than unstressed syllables, an expansion of vowel space and improvement in some aspects of production of voicing, manner and place of articulation were noted one year post-Nucleus stimulation. Loss of auditory feedback results are related to the literature on the effects of postlingual deafness on speech. Nucleus and 3M/House effects on speech are discussed in terms of speech production studies of single-electrode and multichannel patients.

Child↗
PubMed1991

The development of a Children's Implant Profile.

The decision to provide a child with a cochlear implant is quite complex, as it must include consideration not only of the implant itself but also of the habilitative services necessary following the surgical procedure. To provide a systematic means of selecting hearing-impaired children for cochlear implants, a team at Children's Hearing Institute, Manhattan Eye, Ear and Throat Hospital, developed the Children's Implant Profile (ChIP). There is no one profile of a successful implant user--at least 11 factors appear to contribute to successful implantation. In the ChIP, each factor is evaluated on a three-point scale: (1) no concern, (2) mild-to-moderate concern, and (3) great concern. A profile showing "no concern" on all 11 factors denotes clear acceptability of the child as an implant candidate. A profile including several ratings in the "mild-to-moderate concern" category suggests a need for further study to determine if improvements could be made in projected outcomes before initiating surgical procedures. Finally, ratings of "great concern," especially on more than one factor, indicate a very limited probability of successful implant outcomes, at least at the time of evaluation. A case study is presented to demonstrate the relationship between the evaluated factors and to show how the profile is used to address and remedy areas of concern.

Child↗
PubMed1990

Cochlear implant flap complications.

In a series of 52 patients who received cochlear implants, 4 patients suffered flap complications (7.7%). The problems encountered involved the postauricular flap and were usually minor in nature. None required explantation as a direct result of these complications. Flap ischemia in a patient with Cogan's syndrome and vasculitis, two cases of suture extrusion with one having exposure of the implant, and a case of receiver unit magnet extrusion repaired with a vascularized pericranial flap based upon temporalis muscle are presented. Flap design in patients who have had postauricular incisions demands special consideration. Principles useful for avoiding complications as well as their management are discussed.

Adult↗
PubMed1990

A matched-pairs comparison of single and multichannel cochlear implants in children.

Auditory capabilities of Nucleus 22 multichannel cochlear implant users were compared to those of matched 3M/House single-channel users. Six children who received either the 3M/House or Nucleus 22 cochlear implants were separated into three matched pairs. Group 1 consisted of two postlinguistically deafened adolescents, group 2 consisted of two prelinguistically deafened school-age children, and group 3 consisted of two perilinguistically deafened preschoolers. Participants were evaluated using auditory comprehension and discrimination tasks as indicated by the 3M/House and Nucleus 22 protocols. However, only tasks common to both were included here. While the 3M/House single-channel device has been under an IDE for children under the age of 18 years since 1984, the Nucleus 22 multichannel implant only recently became available for this age group. Thus, short-term evaluations at 6 months and 1 year postimplantation have been used for comparison. Two of the three groups indicated that the multichannel users performed as early as the 6-month level; the children in the third group performed equally. These results indicate that multichannel cochlear implants show great promise in deaf children.

Adolescent↗
PubMed1989

The speech of a postlingually deafened teenager during the first year of use of a multichannel cochlear implant.

The speech of a profoundly postlingually deafened teenager was recorded before, immediately after, 3 months after, and 1 year after electrical stimulation with a Nucleus multichannel cochlear implant. Listener tests of target words revealed significant improvement in overall quality over the year. Spectrograms showed less aspiration and better definition of the lower formants. Acoustic measurements indicated immediate change in F0 and gradual changes in syllable duration and some aspects of voicing and manner of articulation. Vowel space shrank steadily over the year, with both first- and second-formant frequencies dropping. Prestimulation results are discussed relative to the literature on the speech of the congenitally hearing impaired. Effects of multichannel electrical stimulation on speech are compared with studies of single-electrode stimulation.

Adolescent↗