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However, cochlear implants still have limitations, such as speech recognition in noisy environments caused by intra-cochlear current spread across different auditory spiral ganglion neurons as a consequence of, e.g., the large distance of the stimulation electrodes to the target cells in a highly conductive environment. Stimulation in cochlear implants is typically done with charge balanced biphasic rectangular current pulses in a monopolar arrangement. However, several studies have shown that a rectangular stimulation pulse is not optimal for stimulating spiral ganglion neurons. For example, stimulation with a ramped pulse, such as a sawtooth pulse, has been shown to be more energy-efficient and achieves a similar threshold profile in spiral ganglion neurons. In this study, a new but simple equivalent electrical circuit model is introduced that describes the complex impedance between two stimulation electrodes of a cochlear implant with high accuracy (mean relative error\u2009\u2264\u20098%). Based on this bipolar model, a monopolar equivalent electrical circuit model is developed to describe the stimulation between one stimulation electrode and a counter electrode located outside the cochlea. These two models now allow for analyzing the effect of stimulation pulse shape on power distribution in cochlear implant electrodes and surrounding tissue providing a tool for investigating stimulation efficiency with respect to energy losses in the cochlear implant electrode.<\/jats:p>","DOI":"10.1038\/s41598-025-04840-5","type":"journal-article","created":{"date-parts":[[2025,6,20]],"date-time":"2025-06-20T09:09:14Z","timestamp":1750410554000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Electrical equivalent circuit for analyzing the effect of signal shape on power distribution in cochlear implant electrodes and surrounding tissue"],"prefix":"10.1038","volume":"15","author":[{"given":"Merle","family":"Sehlmeyer","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mariia","family":"Makarenko","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nele","family":"Schoerner","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mit B.","family":"Bhavsar","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tatiana","family":"Blank","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hans J\u00fcrgen","family":"Maier","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrej","family":"Kral","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hannes","family":"Maier","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stefan","family":"Zimmermann","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2025,6,20]]},"reference":[{"key":"4840_CR1","doi-asserted-by":"publisher","first-page":"629","DOI":"10.1097\/01.mao.0000281803.36574.bc","volume":"28","author":"JB Firszt","year":"2007","unstructured":"Firszt, J. 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