###### Abstract  
This research aims to determine whether a neural response telemetry (NRT) threshold determines the success of surgery. Furthermore, we examined whether the patient's age, the etiology of their hearing loss, the depth of the electrode insertion, and a slow electrode insertion affect the result of postoperative speech audiometry (PSA). A total of 23 patients that had operations in a tertiary medical centre were included in the research. All of them received a slim straight electrode that was inserted through the round window into the lateral part of scala typnani The duration of the insertion was consistently 2 min in 52.2% and less than 2 min in 47.8% of cases. Statistical analyses were performed in the IBM SPSSTM program. Patients that were diagnosed with sensorineural hearing loss (SNHL) had statistically lower average NRT threshold values in comparison to patients diagnosed with otsclerosis (\(t=3.069\); \(p=0.034\)). The depth of electrode insertion is inversely proportional to the average of all NRT thresholds (\(r=-0.464\); \(p=0.026\)). No correlation was found between slow electrode insertion and postoperative average values of tone audiometry (U = 44.000; \(p=0.300\)). No statistically significant correlation could be drawn between the average of all NRT thresholds and postoperative speech audiometry (rho = \(-0.070\); \(p=0.751\)). cochelear implant; neural response telemetry; speech perception; audiometry; hearing loss; hearing preservation; slim straight electrode; insertion depth; slow electrode insertion +
Footnote †: journal: Medical Centre Maribor, 2000 Maribor, Slovenia  
Footnote †: journal: Medical Centre Maribor, 200 Maribor, Slovenia  
Footnote †: journal: Medical Centre Maribor, 2000 Maribor, Slovenia  
Footnote †: journal: Medical Centre Maribor, 200 Maribor, Slovenia  
Footnote †: journal: Medical Centre Maribor, 2000 Maribor, Slovenia
An important factor that affects speech outcomes of patients with CIs is the condition of the auditory nerve [3]. Neurons rapidly propagate signals over large distances. There is a threshold value for each neuron to be depolarized. By reaching the threshold value, electrical pulses called action potentials are generated in the neuron [6]. Neural response telemetry (NRT) is an objective method, performed intraoperatively, which captures the action potential of the distal part of the auditory nerve in CIs and thus represents a direct method of assessing the in vivo functional characteristics of ganglion cells and other auditory neural structures. The action potential that is reflected by NRT represents the synchronized firing of many auditory nerve fibers and consequently illustrates the sum of the electrical activity of hundreds of neurons [7]. The electrode in the cochlear implant is a major factor in hearing performance as it represents the interface between the cochlear implant and the recipient's auditory neural pathways. The long-term advantages of the slim straight electrode are low-frequency preservation of residual hearing, significant improvement of speech understanding in quiet and noisy environments, avoidance of intracochlear trauma, and greater adaptability in anatomical and pathological variations where the cochlea is not suitable for the period-olar electrode insertion [8]. Furthermore, the findings of [PERSON] et al. suggest that the choice of electrode does not significantly affect the outcome of the procedure [9]. At the top, the diameter is only 0.3 mm, and the depth of insertion could vary in cases of hearing preservation. It has 22 medial-facing, half-banded platinum electrode contacts positioned over 20 mm [10]. Our research aims to determine whether a low intraoperative NRT threshold determines the surgery's success. Furthermore, we aimed to explore whether the patient's age, the etiology of their hearing loss, the depth of the electrode insertion, and the slow insertion of the electrode affect the results of postoperative speech audiometry (PSA). Our research advantage lies in a unified surgical approach.