Affiliations: [a] Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran | [b] Engineering Faculty, Shahed University, Tehran, Iran
Abstract: BACKGROUND: Speech synthesis models have been considered as viable
tools for performance evaluation of cochlear stimulation algorithms, due to
the difficulties of clinical tests. OBJECTIVE: The present study has developed a tool that can be used
before any audio signal reconstruction algorithm, which shows more
conformity with the electrophysiological parameters of the patient in
evaluation of the cochlear implant stimulation algorithms. METHODS: In this method, excitable nerve fiber characteristics such
as stimulation threshold and effective refractory period have been
considered in the signal pre-reconstruction process. This algorithm subsumes
the user's biological parameters (e.g., the manner of distribution of the
remaining intact nerve fibers) as well as the stimulation signal parameters
(e.g., stimulation rate, pulse width, amplitude of stimulation, the distance
between stimulation electrode and fibers) in the signal pre-reconstruction. RESULTS: Effect of changes in these parameters can be observed by
the number of excited fibers, which is directly related to the signal
intensity and pitch frequency perceived by the user. The obtained results
from simulations are in accordance with previous clinical findings. Also,
the ability of the proposed tool can be seen by the correspondence between
the results obtained from the proposed model and the amplitude growth
functions of the cochlear implant users. CONCLUSIONS: This paper has introduced a tool for signal
reconstruction from electrical stimulation so that a more comprehensive
criterion for examination of the stimulating algorithms in cochlear implant
can be achieved.
