Objective: To investigate the role of intraoperative cochlear nerve (CN) electric monitoring with MED-EL intracochlear test electrode (ITE) in assessing the CN functional integrity. Setting: Tertiary referral center. Patients: Patients with intrameatal or 2 to 13 mm in the cerebello-pontine angle vestibular schwannoma (VS), not suitable for hearing preservation surgery but eligible for tumor resection via translabyrinthine approach and simultaneous cochlear implant (CI) rehabilitation. Intervention: ITE was used to register electrically evoked auditory brainstem response (eABR) before and after VS resection. All patients with anatomical preservation of CN underwent CI, regardless of eABR results, which served as the index test and was compared with postoperative sound perception by CI stimuli (gold standard test). Results: Twelve of seventeen cases allowed anatomical preservation of CN and were considered for the study. Seven of twelve cases demonstrated sound detection with CI, and six of twelve showed some degree of speech discrimination. eABR test with ITE achieved an accuracy of 66.7%, a sensitivity of 42.9%, and a specificity of 100%. Positive and negative predictive values were 100% and 55.6%, respectively. Conclusion: When eABR can be evoked with ITE, the attempt of CI was likely to be successful, whereas in cases of eABR absence, other factors should be considered to reduce unsuccessful CI and not preclude rehabilitation in patients who would benefit from CI. Further studies and longer follow-up are needed to analyze the role of ITE in VS surgery with CI.

Background: Auditory brainstem responses (ABRs) are widely used for objective hearing threshold estimation in both adults and children. Click and CE-Chirp stimuli differ substantially in cochlear activation and neural synchrony, yet their relative performance in patients with ski-sloping hearing loss remains insufficiently characterized, particularly with regard to pediatric diagnostic implications. Methods: This study compared ABRs elicited by click and CE-Chirp stimuli in adults with ski-sloping sensorineural hearing loss. The same comparison was also performed in a pediatric cohort including hearing-impaired and normal-hearing children. Adult subjects were further stratified according to audiometric configuration (DROP 1 kHz vs. DROP 2 kHz). ABR thresholds, wave V latency, amplitude, and detectability were analyzed across stimulus types and intensity levels. Associations between ABR thresholds and behavioral audiometric measures were also examined. Results: In adults with ski-sloping hearing loss, CE-Chirp stimulation yielded significantly lower ABR threshold estimates than click stimulation, particularly in the DROP 2 kHz subgroup, and showed stronger correlations with behavioral pure-tone averages across low-, mid-, and high-frequency ranges. Wave V latencies were consistently shorter with CE-Chirp stimulation, while wave V amplitudes did not differ significantly between stimuli at suprathreshold levels. In children, ABR thresholds obtained with CE-Chirp were generally equal to or lower than those obtained with clicks, although statistical significance was limited by sample size. CE-Chirp stimulation was associated with shorter wave V latencies in both hearing-impaired and normal-hearing children and produced larger wave V amplitudes at selected suprathreshold intensities in hearing-impaired children. Conclusions: Click and CE-Chirp stimuli provide complementary information in ABR assessment. While click stimulation remains essential for robust waveform identification, CE-Chirp stimulation appears to offer advantages in threshold estimation and neural synchrony, particularly in ski-sloping hearing loss and pediatric evaluations. Discrepancies between click- and CE-Chirp-derived ABR thresholds should not be attributed solely to maturational or synchrony-related factors but may warrant further frequency-specific audiological assessment to optimize diagnosis and rehabilitation strategies.

Objective: Modern hearing devices modify speech beyond simple amplification, whereas Real-Ear Measurement (REM) primarily quantifies the sound level delivered to the ear as a function of frequency. SpettroREM was developed to characterize spectral and temporal signal structure by comparing each aided recording with the corresponding unaided recording, termed the Individual Acoustic Reference (IAR). This study evaluates the stability and test–retest reliability of the unaided reference and characterizes the external recording pathway; it does not assess aided–unaided differences. Design: The descriptor framework was developed from preliminary auditory and visual analysis of four unaided ear-canal recordings. Established acoustic measures available in Praat were progressively extended to predefined speech segments, local measurements, derived spectral and temporal measures, vowel geometry, envelope dynamics, and speech contrast. The resulting exploratory library comprised 44 measures; 37 were designated as the principal descriptor set and organized into six complementary domains, whereas seven derived or partially overlapping measures were retained as exploratory outputs. REM recordings acquired using AURICAL FreeFit (Natus) were processed through a semi-automated Praat workflow. Descriptor variability was characterized using descriptive distributional measures and, where appropriate, coefficients of variation. Test–retest reliability was assessed using ICC(A,1) with 95% participant-level bootstrap confidence intervals, together with mean absolute differences, Bland–Altman limits of agreement, and repeatability coefficients. The external recording pathway was assessed through electrical loopback and acoustic comparison tests. Study Sample: This study included two complementary datasets: 26 unaided ear recordings for baseline descriptor characterization and bilateral test–retest recordings from 25 participants. The primary reliability analysis included 24 right ears because one right ear was excluded owing to tympanic membrane perforation. Test–retest recordings from all 25 contralateral left ears were analyzed separately as a within-sample sensitivity analysis to assess the robustness of the principal reliability pattern to the choice of ear used for the primary analysis. Right- and left-ear observations were not pooled. Results: Global spectral descriptors showed limited variability and the most consistent test–retest agreement in the primary right-ear analysis. In the exploratory post hoc tier classification, the seven Core descriptors showed ICC(A,1) values ranging from 0.906 to 0.984, with the lower bound of the 95% confidence interval remaining ≥0.75 for all Core descriptors. Mean absolute test–retest differences for the LTASS bands were 0.31 dB at 0–1 kHz, 0.50 dB at 1–4 kHz, and 0.88 dB at 4–8 kHz. The contralateral sensitivity analysis reproduced high repeatability of the three LTASS band levels, with ICCs ranging from 0.835 to 0.940, although it did not constitute an independent replication. Repeatability was less consistent for several recording-level-dependent, segmental, vowel-derived, and temporal-envelope descriptors, some of which were occasionally non-evaluable because of insufficient signal energy. Electrical testing showed no relevant spectral alteration or clipping in the cable–audio interface–Praat segment under the tested settings. External-recording repeatability was high across the primary mono-cable validation and the secondary stereo bridge experiment (r = 0.976–0.998), but frequency-dependent differences were observed between the OTOsuite display and the simultaneous external recording. The two acquisition outputs should therefore not be considered numerically interchangeable. Conclusions: Under standardized acquisition conditions, selected properties of the unaided IAR, particularly its global spectral organization, can be measured with good test–retest repeatability. Technical assessment supports internally consistent measurements using the tested AURICAL FreeFit–mono TS cable–external audio interface–Praat pathway but does not establish absolute spectral accuracy or numerical equivalence across acquisition outputs or platforms. The Core, Candidate, and Secondary classification is exploratory, post hoc, and requires confirmation in an independent sample. This study provides a preliminary reliability assessment of the unaided reference and its development-derived 37-descriptor library; it does not validate the complete SpettroREM method. Direct aided–unaided studies are required to establish sensitivity to device-induced transformations, aided-recording repeatability, clinical and perceptual relevance, and the most informative non-redundant descriptor subset.