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Hangzhou, China

Wang N.,University of Minnesota | Wang N.,Nurotron Biotechnology | Kreft H.,University of Minnesota | Oxenham A.J.,University of Minnesota
JARO - Journal of the Association for Research in Otolaryngology

The loudness of a tone can be reduced by preceding it with a more intense tone. This effect, known as induced loudness reduction (ILR), has been reported to last for several seconds. The underlying neural mechanisms are unknown. One possible contributor to the effect involves changes in cochlear gain via the medial olivocochlear (MOC) efferents. Since cochlear implants (CIs) bypass the cochlea, investigating whether and how CI users experience ILR should help provide a better understanding of the underlying mechanisms. In the present study, ILR was examined in both normal-hearing listeners and CI users by examining the effects of an intense precursor (50 or 500 ms) on the loudness of a 50-ms target, as judged by comparing it to a spectrally remote 50-ms comparison sound. The interstimulus interval (ISI) between the precursor and the target was varied between 10 and 1000 ms to estimate the time course of ILR. In general, the patterns of results from the CI users were similar to those found in the normal-hearing listeners. However, in the short-precursor short-ISI condition, an enhancement in the loudness of target was observed in CI subjects that was not present in the normal-hearing listeners, consistent with the effects of an additional attenuation present in the normal-hearing listeners but not in the CI users. The results suggest that the MOC may play a role but that it is not the only source of these loudness context effects. © 2016, Association for Research in Otolaryngology. Source

Nurotron Biotechnology | Date: 2012-06-05

Computer software for operating eye implants, hearing aids, and cochlear implants. Medical devices, namely, eye implants, hearing aids, cochlear implants and computer operating software sold as a unit.

Lu T.,University of California at Irvine | Djalilian H.,University of California at Irvine | Zeng F.-G.,University of California at Irvine | Chen H.,Nurotron Biotechnology | Sun X.,Nurotron Biotechnology
Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS

An integrated vestibular-cochlear implant can be rapidly prototyped and clinically tested by modifying an existing modern cochlear implant. The modifications include addition of gyroscope sensors and reallocation of several electrodes that are normally used for auditory nerve stimulation to the semicircular canals, while sharing the external DSP processor and the internal receiver/stimulator. This paper discusses the validation issues related to hardware and software design that arise in integrating electric hearing and balance onto a single device. The device's initially targeted population will be deaf individuals who also have vestibular impairment since there is a strong ethical justification for vestibular implantation along with minimal additional surgical risk. Because of widespread usage of ototoxic drugs and unique genetic mutations, the patient population with both impaired hearing and balance function is especially prevalent in Asian countries such as China and India. Should such an integrated vestibular-cochlear implant be verified, it could be used to restore balance or treat a wide array of vestibular disorders. © 2011 IEEE. Source

A programmable cochlear implant system utilizes multiple-resolution current sources and flexible data-encoding scheme for transcutaneous transmission. In certain embodiments, the number of current sources may be equal to or greater than 2, but equal or less than N1, where N is the number of electrodes. The multi-resolution current source may introduce offset currents to achieve perceptually-based multiple resolutions with high resolution at low amplitudes and low resolution at high amplitudes. The flexible data-encoding scheme may allow arbitrary waveforms in terms of phase polarity, phase duration, pseudo-analog-waveform, while producing high-rate and high-temporal-precision stimulation. In one embodiment, a 2-current-source system may support simultaneous and non-simultaneous stimulation as well as monopolar, bipolar, pseudo-tripolar, and tripolar electrode configurations.

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