Consonant recognition as a function of the number of stimulation channels in the Hybrid short-electrode cochlear implant

Abstract

Consonant recognition was measured as a function of the number of stimulation channels for Hybrid short-electrode cochlear implant (CI) users, long-electrode CI users, and normal-hearing (NH) listeners in quiet and background noise. Short-electrode CI subjects were tested with 1-6 channels allocated to a frequency range of 1063-7938 Hz. Long-electrode CI subjects were tested with 1-6, 8, or 22 channels allocated to 188-7938 Hz, or 1-6 or 15 channels from the basal 15 electrodes allocated to 1063-7938 Hz. NH listeners were tested with simulations of each CI group/condition. Despite differences in intracochlear electrode spacing for equivalent channel conditions, all CI subject groups performed similarly at each channel condition and improved up to at least four channels in quiet and noise. All CI subject groups underperformed relative to NH subjects. These preliminary findings suggest that the limited channel benefit seen for CI users may not be due solely to increases in channel interactions as a function of electrode density. Other factors such as pre-operative patient history, location of stimulation in the base versus apex, or a limit on the number of electric channels that can be processed cognitively, may also interact with the effects of electrode contact spacing along the cochlea.

Restoring autophagic flux attenuates cochlear spiral ganglion neuron degeneration by promoting TFEB nuclear translocation via inhibiting MTOR

“…As a consequence of cochlear sensory epithelial cell loss, the degeneration of cochlear nerve fibers and SGNs is, in essence, atrophy from disuse, which results from the loss of the target organ and neurotrophic factors [1]. With the aid of stem cell transplantation [2], gene rescue [3], neurotrophic factor inner ear administration [1] and other means, hair cell regeneration has already been achieved in many scientific experiments. Hair cell regeneration in vivo is meaningless if the regenerated hair cells cannot be innervated by SGNs in the cochlea.…”

“…The number of surviving SGNs determines the effect of cochlear implantation. Therefore, to achieve better hearing rehabilitation via cochlear implantation, a required number of surviving SGNs is necessary [2,3]. To rehabilitate hearing diminished by sensorineural hearing loss, preventing or alleviating the degeneration of cochlear nerve fibers and SGNs following sensory epithelial cell loss is crucial.…”

Delayed loss of hearing after hearing preservation cochlear implantation: Human temporal bone pathology and implications for etiology

“…When residual hearing is preserved, patients may utilize both electric and acoustic hearing in the implanted ear. The benefits of combined electric and acoustic hearing in the same ear include better hearing in background noise and in quiet, and better spatial localization (Reiss, Turner, Karsten, Erenberg, Taylor & Gantz 2012a; Gantz et al 2009; Turner et al 2008; Gantz & Turner 2004; Gifford et al 2014; Kiefer et al 2005). These benefits occur when the preserved hearing is in the functional acoustic range (less than 90 dB pure tone average for 125Hz to 1.5KHz) (Roland et al submitted 2015).…”

“…Delayed post-implantation hearing loss has been reported in 15 to 56% of patients with initially preserved hearing (Gifford et al 2013; Reiss, Turner, Karsten, Erenberg, Taylor & Gantz 2012b; Van Abel et al 2015; Lenarz et al 2013; Adunka et al 2013). In the Hybrid 10 clinical trial, for example, although only 2 out of 87 patients were found to have total hearing loss at the initial one month follow up, an additional 6 patients progressed to total hearing loss between 3 and 24 months after implantation(Gantz et al 2009).…”

The quest for restoring hearing: Understanding ear development more completely

“…Reconstitution of the OC would require an adjustable strategy that takes the local variation of the OC deterioration into account. Such a strategy could start with mapping precisely the residual hearing capacity currently used with short cochlear implants . Even more desirable would be increased imaging resolution to identify not only residual cell types and their distribution, but have precise measurements of the apparently very variable cochlear duct and hearing loss‐related cellular loss .…”