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Biomedical subjects

I Hochberg

Publications and source records attributed to I Hochberg.

At least 19 recordsLinked to original sources

Effects of noise and noise suppression on speech perception by cochlear implant users.

The recognition of phonemes in consonant-vowel-consonant words, presented in speech-shaped random noise, was measured as a function of signal to noise ratio (S/N) in 10 normally hearing adults and 10 successful adult users of the Nucleus cochlear implant. Optimal scores (measured at a S/N of +25 dB) were 98% for the average normal subject and 42% for the average implantee. Phoneme recognition threshold was defined as the S/N at which the phoneme recognition score fell to 50% of its optimal value. This threshold was -2 dB for the average normal subject and +9 dB for the average implantee. Application of a digital noise suppression algorithm (INTEL) to the mixed speech plus noise signal had no effect on the optimal phoneme recognition score of either group or on the phoneme recognition threshold of the normal group. It did, however, improve the phoneme recognition threshold of the implant group by an average of 4 to 5 dB. These findings illustrate the noise susceptibility of Nucleus cochlear implant users and suggest that single-channel digital noise reduction techniques may offer some relief from this problem.

Adult

Perception of speech pattern contrasts using a multichannel cochlear implant.

The ability to perceive for suprasegmental and eight segmental speech pattern contrasts was measured on 16 adult cochlear implantees using the Nucleus multichannel prosthesis with either F0-F2 (n = 9) or F0-F1-F2 (n = 7) coding. The results of this study indicated the following: (1) The Nucleus device provided significant access to the majority of suprasegmental and segmental speech contrasts. (2) Both one- and two-format coding strategies provided good access to speech pattern contrasts. (3) Considerable intersubject differences in performance were observed, but there was no evidence to suggest that these were related to either processing scheme. (4) Although the accessibility of speech contrasts varied, the pattern of perceptual performance was interpreted in terms of an acoustic/phonetic hierarchy. (5) The Speech Pattern Contrast (SPAC) test appears to be a practical procedure for analyzing the perception of phonologically salient information about the suprasegmental and segmental components of speech.

Adult

Effect of text complexity on connected discourse tracking rate.

The effect of three levels of text complexity upon connected discourse tracking rates was investigated in normal listeners who tracked by lipreading alone and by lipreading with auditorily presented voice pitch. Text complexity affected connected discourse tracking under both lipreading conditions, with tracking rates decreasing as the level of text complexity increased. The improvement in tracking rate with the addition of voice pitch information was found to be invariant over changes in text complexity when expressed as a simple difference between the two tracking rates.

Female

Children's perception of speech in reverberation.

Recordings of nonsense syllables (VCV construction) were presented to groups of children aged 5, 7, 9, 11, and 13 years and young adults under monaural (reverberation time = 0.6s) and binaural (reverberation times = 0, 0.4, and 0.6 s) conditions of reverberation. Phoneme identification performance was affected by age, reverberation, and mode of presentation (monaural versus binaural). The major findings were (1) phoneme identification scores in reverberant conditions improved with increasing age and decreased with increased reverberation time; (2) children's performance in reverberant conditions did not reach asymptote until age 13; (3) binaural performance was consistently better than monaural performance for all age groups, with 5-year-olds showing the largest binaural advantage.

Adolescent

Post-meningitic hearing loss: report on three cases.

Three children with post-meningitic hearing loss were seen for evaluation and aural rehabilitation over a 4-yr period. Fluctations in hearing levels during that time period were noted. The hearing of one child improved, while that of the other two children decreased. Changes in sensitivity were documented and discussed with reference to the habilitation process. The need for frequent monitoring and for otologic intervention in the post-meningitic child is emphasized.

Child, Preschool

The cognitive use of language by disadvantaged and nondisadvantaged children.

The cognitive use of language was evaluated among sixth-grade disadvantaged and nondisadvantaged children by eliciting spontaneous language samples in response to a series of 14 auditory stimuli, each depicting one or more human and/or mechanical sounds. -responses were analyzed according to the following dimensions: (a) units of thought: (b) concept formation; (c) parts of the sound responded to; (d) integration; (e) manner of verbalization; and (f) identification. Disadvantaged children manifested significantly fewer units of thought than their advantage counterparts. Several significant trends were noted for several of the remaining dimensions and were discussed. The general cognitive styles of the subject groups were related to the field-dependency-independency dichotomy described in the literature by Witkin and his associates.

Association