## 1 Introduction  
The global prevalence of hearing loss is a significant public health concern, affecting over 5% of individuals worldwide, with an anticipated doubling of this number by 2050 [1]. The cochlea function generates a sense of hearing by transforming the sound waves into mechanical vibrations of the hair cells and subsequently into electrical pulses to provide hearing sensation. Dysfunction of the cochlea may result in an impaired understanding of speech which is highly invalidating for professional, social, emotional, and cognitive well-being. Cochlear implant (CI) is a partially invasive neuromodulation technique that restores hearing loss through electrical stimulation of the hearing nerve from within the cochlea, as shown in Figure 1A. The electrode array (EA) of the CI is surgically inserted into the scala typmari (ST) of the cochlea to replace the function of the damaged hair cells. The clinical results have shown that the EA insertion process during the CI surgery is crucial for patient outcomes [2]. Thus, accurate electrode placement in the ST is a key parameter for hearing [3]. Misplacement may cause damage to intracochlear structures and compromise the remaining hearing. If the electrode touches the cochlea nearby layers, further hearing loss and insertion trauma may occur. It has been shown that electrode insertion trauma was observed in one in every three implantations [4]. Since the human cochlea is surrounded by bone, it is extremely challenging to assess the position of the EA within the cochlea during the insertion. Moreover, the interaction between the EAand the cochlear structures is invisible due to the limitations of current electrode insertion guidance technologies. Thus, the EA insertion process primarily relies on the surgeon's tactile feedback and experience [5] although there are many visual inspections of the EA guidance techniques [3]. Computed tomography (CT) imaging is one of the methods to determine EA positioning but is not routinely performed due to the radiation risks [6]. Alternatively, the EA position can be assessed in real time by electrically evoked neural responses, electric field imaging, or impedance variations [7]. The results of the clinical studies have shown that the results for evoked neural responses in assessing EA positioning are highly variable [8]. Thus, this method may not be a reliable contributor to determining EA position guidance during insertion to the cochlea. Although the major error position of the electrodes in the ST could be registered using electric field imaging, it was not utilized to predict the positions of the electrodes in the ST [9]. It has been shown that bioelectrical impedance variations can be used as a biomarker for monitoring EA position in the ST [3; 10; 11; 12; 13] due to the higher conductivity of the ST compared to other layers. The hypothesis was that the measured electrode impedance to the ground should be higher when an electrode approaches the cochlea wall compared to when the electrode is in the middle of the scala [14]. The overview of experimental CI simulation and impedance recording procedures is highlighted in Figure 2A. Conventional clinical techniques may not be feasible to determine the EA positioning due to the associated risks. Alternatively, bio-computational modeling can be used to investigate the optimal position of the EA insertion [3; 15]. Although the bio-computational modeling studies of CI have been carried out under the quasi-static solution (QS) by ignoring capacitive, inductive, and wave propagation effects [3; 15; 16], it has been indicated that the electrical impedance of body tissues depends on the alternating current signal frequency [17; 18; 19]. Also, the results based on the experiments showed that the capacitive component of impedance can affect the shape and amplitude of the voltage waveform for different applications [18]. In particular, the QS may not always be appropriate due to short-duration pulses (\(\sim\)100 us) [11; 12; 13].