House Institute Foundation

The ability to segregate speech streams in challenging listening environments, often referred to as the "cocktail party effect," is critical for children learning effective communication, especially in noisy classroom settings. This developmental process, influenced by factors such as hearing sensitivity, cognitive abilities, and acoustic cues, has not been thoroughly examined in relation to hearing at frequencies above 8 kHz, to which children are exquisitely more sensitive than adults. This represents a critical gap, as emerging studies reveal the significant detrimental effects of filtering out this information. The present study investigated the functional role of extended high-frequency (EHF) sensitivity in speech stream segregation in normal-hearing children aged 4-14 years. Using digit triplets to reduce cognitive load, performance on speech tasks were measured across four segregation cue conditions: baseline (co-located, talker-sex matched), talker-sex cue (talker-sex mismatched), spatial cue (spatially separated target and maskers), and combined (talker-sex cue and spatial cue). Results demonstrate that EHF sensitivity uniquely contributes to improved SRTs in baseline and talker-sex cue conditions, underscoring its importance in situations where talker-specific cues are crucial for stream segregation. However, EHF sensitivity did not influence SRTs in the spatial or combined cue conditions, nor did it significantly affect release from masking in any conditions. These findings suggest that while EHF sensitivity plays a key role in segregating speech streams, its contribution may be less prominent when salient spatial cues are available. This research highlights the importance of EHF sensitivity in children for utilization of talker-specific cues when segregating competing speech in complex listening environments.

In preclinical research, animals are used to perform clinical experiments. The use of large animals with human-like anatomies and structural size appears to be essential. For auditory function research, we needed to identify an animal model whose dimensions are close to those of the human inner ear for future research. In the present study, we investigated measurements of the human and sheep inner ear using 3 T Magnetic Resonance Imaging (MRI) to evaluate the suitability of a sheep model for studying the inner ear.

Inner ears were compared between 8 ears from 4 normal humans (women) and 8 ears from 4 normal sheep (female). Cranial MRI of both species' cochleae were acquired and analyzed, with specific measurements for key anatomical features, including the cochlea length and width, the length and width of the inner auditory canal, the number of spiral turns of the cochlea and the cochlea volume. The size ratios between sheep and human cochlear structures were calculated and compared.

Overall cochlear dimensions of the sheep were approximately 2/3 that of human cochleae across most measurements, except for the internal auditory canal. The internal auditory canal of the sheep was 1/3 of the size of that in humans. The number of spiral turns in the cochlea was equivalent between the two species.

Given the proportionally similar dimensions to humans, the sheep cochlea appears to be a promising model for inner ear research, specifically to develop pathological models, to study the pathophysiological mechanisms of inner ear diseases, and/or to improve treatment with implantable prostheses.

To evaluate the efficacy and safety of awake stapedectomy under hypnoanalgesia (HA) compared to general anesthesia (GA) and local anesthesia (LA) in patients with otosclerosis.

A single-center retrospective study included 131 adult patients (mean age: 49 years; 78% female) who underwent laser stapedectomy between 2020 and 2022: 58 GA, 23 LA, 50 HA. Primary outcome measures comprised operative room occupancy time, anesthetic consumption, and postoperative audiometric results.

HA significantly reduced operative room occupancy time (73.5±18.6min vs 103.7±24.6min in GA, P<0.001; vs 81.8±20.5min in LA, P=0.092), stapedectomy duration (39.9±12.4min vs 48.9±21.5min in GA, P=0.0252; vs 38.9±13.2min in LA, P=0.4601), preoperative time (30.2±9.5min vs 45.7±9.5min in GA, P<0.001; vs 38.6±12.2min in LA, P=0.0022), and recovery room time (26±15.1min vs 67.5±20.7min in GA, P<0.001; vs 47.4±20.7min in LA, P<0.001). HA also significantly reduced remifentanil consumption (169.8±101.6μg vs 848.6±308.8μg in GA, P<0.001; vs 323.9±94.4μg in LA, P<0.001). Postoperative audiometric outcomes showed no significant differences between groups.

Hypnoanalgesia for awake stapedectomy provided significantly greater efficacy compared to general anesthesia, reducing operative time and anesthetic consumption, with comparable audiometric outcomes.