Cochlear Limited

About: Cochlear Limited is a company organization based out in Sydney, New South Wales, Australia. It is known for research contribution in the topics: Cochlear implant & Hearing loss. The organization has 1290 authors who have published 1479 publications receiving 33109 citations. The organization is also known as: кохлеарные Americas & COCHLEAR LIMITED.

Facial Nerve Stimulation with Cochlear Implantation

Abstract: 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.

Speech understanding in noise with a Med-El COMBI 40+ cochlear implant using reduced channel sets.

Abstract: OBJECTIVE: The objective of the investigation described in this paper was the determination of the number of (widely spaced) active electrodes needed for users of a COMBI 40+ cochlear implant to achieve asymptotic performance in the recognition of speech against a background of wideband noise. DESIGN: This study measured the performance in speech tests of patients using the Med-El implementation of continuous interleaved sampling with widely spaced electrode pair subsets of 2, 3, 4, 6, 8, and 10 out of a possible maximum of 12. An eight-vowel test, a 16-consonant test, and BKB sentences were presented against a background of pink noise. Additionally, AB monosyllabic words were presented both in quiet and in noise to processors with 6, 8, and 11 widely spaced electrodes. 11 subjects participated in the study. RESULTS: Using moderate signal-to-noise ratios, for these patients the curve relating percentage score to increasing numbers of active channels approached an asymptote before the 10-channel data point was reached. Asymptotic performance was achieved using four channels for consonants, and eight channels for sentences. Understanding of monosyllabic words reached a maximum value at a similar number of channels for both quiet conditions and against a background of pink noise, and the mean increase in test score between 6 and 11 channels was only 7%. CONCLUSIONS: These results are similar to those of previous experiments carried out in quiet listening conditions. The data suggest that 12 frequency channels (the number implemented by the COMBI 40+ cochlear implant) are more than adequate for users to achieve asymptotic performance levels in clinical speech tests applied in the presence of wideband noise at moderate signal-to-noise ratios.

The Temporalis Pocket Technique for Cochlear Implantation: An Anatomic and Clinical Study

Abstract: Objective:To describe the surgical anatomy and clinical outcomes of a technique for securing cochlear implant receiver/stimulators (R/S). Receiver/stimulators are generally secured by drilling a custom-fit seat and suture-retaining holes in the skull. However, rare intracranial complications and R/S

Use it or lose it? Lessons learned from the developing brains of children who are deaf and use cochlear implants to hear.

Abstract: In the present paper, we review what is currently known about the effects of deafness on the developing human auditory system and ask: Without use, does the immature auditory system lose the ability to normally function and mature? Any change to the structure or function of the auditory pathways resulting from a lack of activity will have important implications for future use through an auditory prosthesis such as a cochlear implant. Data to date show that deafness in children arrests and disrupts normal auditory development. Multiple changes to the auditory pathways occur during the period of deafness with the extent and type of change being dependent upon the age and stage of auditory development at onset of deafness, the cause or type of deafness, and the length of time the immature auditory pathways are left without significant input. Structural changes to the auditory nerve, brainstem, and cortex have been described in animal models of deafness as well in humans who are deaf. Functional changes in deaf auditory pathways have been evaluated by using a cochlear implant to stimulate the auditory nerve with electrical pulses. Studies of electrically evoked activity in the immature deaf auditory system have demonstrated that auditory brainstem development is arrested and that thalamo-cortical areas are vulnerable to being taken over by other competitive inputs (cross-modal plasticity). Indeed, enhanced peripheral sight and detection of visual movement in congenitally deaf cats and adults have been linked to activity in specific areas of what would normally be auditory cortex. Cochlear implants can stimulate developmental plasticity in the auditory brainstem even after many years of deafness in childhood but changes in the auditory cortex are limited, at least in part, by the degree of reorganization which occurred during the period of deafness. Consequently, we must identify hearing loss rapidly (i.e., at birth for congenital deficits) and provide cochlear implants to appropriate candidates as soon as possible. Doing so has facilitated auditory development in the thalamo-cortex and allowed children who are deaf to perceive and use spoken language.

The Nucleus 22-channel cochlear implant system.

Abstract: This is a publisher’s version of an article published in Ear and Hearing 1991. This version is reproduced with permission of Lippincott Wilkins & Williams.