Search PubMedSearch

PubMed · 3878092

Cochlear implant comparisons.

Abstract

The implantation of an electrode into the cochlea of profoundly hearing-impaired adults now promises to be a viable alternative for rehabilitation. In this article we describe six different kinds of cochlear implants, the single-channel devices developed in Los Angeles, Stanford, and Vienna, and the multichannel devices developed in Melbourne, San Francisco, and Utah. We then present results from our own patients implanted with the Los Angeles, Vienna, and Melbourne cochlear implants. All systems provide information about environmental sounds and prosody, which can improve lip-reading ability. Only our patients implanted with the Melbourne system have been able to recognize words in unknown sentences, although others have reported such spectacular performance with single-channel devices. We stress the importance of recorded tests, of material that is unfamiliar to the patient, and of avoiding multiple presentations of the test material.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

B J Gantz, R S Tyler. 1985. Cochlear implant comparisons.. https://pubmed.ncbi.nlm.nih.gov/3878092/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Attempts to develop an efficient speech test in fully modulated noise.

An earlier developed speech test with sentences in noise (Hagerman. 1982) was modified in an attempt to further increase its efficiency. The noise was thus changed to be fully modulated and the speech-to-noise ratio of each word was controlled in order to make all the words equally difficult both within and between lists. The new version was tested on 10 normal-hearing subjects. The 10 lists were equally difficult, but compared to the old material the reliability was worse, the learning effect was greater, and the slope of the intelligibility function was less than half despite efforts to maintain the quality of the test. Identical masking signals for identical words in the various lists seem to increase the learning effect. The strongly modulated noise seems to give shallow intelligibility functions for separate words and thus also for complete lists.

Audiometry, Speech

Quality ratings for frequency-shaped peak-clipped speech: results for listeners with hearing loss.

Peak clipping is a common form of distortion in hearing aids and can reduce the subjective quality of the amplified speech. In a previous study involving listeners with normal hearing (Kates & Kozma-Spytek, 1994), the effect of peak clipping on speech quality ratings was studied using sentence test materials that were filtered using three different frequency response contours and then clipped at four different clipping levels. The present study extends the quality ratings to include those from a group of listeners having moderate to profound hearing impairments. The experimental results indicate that the clipping level, and the interaction of the frequency-response shaping with the clipping level, significantly affects speech quality. It is also shown that the distortion effects on speech quality for the listeners with impaired hearing can be modeled by a distortion index computed from the magnitude-squared coherence of the speech-processing system in response to a shaped-noise input signal. The distortion-index weights derived for the group of listeners with impaired hearing, however, differ substantially from those derived for listeners with normal hearing, and substantial inter-listener variation was also observed.

Audiometry, Speech