Digital Gaze and Vicarious Trauma Among Intensive Care Unit Nurses in Alarm-Monitoring Ecologies: Qualitative Interview Study.

Acoustic communication plays a vital role in courtship and reproductive success of many vertebrate species. For example, in songbirds such as the Carolina chickadee () and the tufted titmouse (), males produce vocalizations to attract females during the breeding season []. These behaviors are accompanied by seasonal changes in auditory sensitivity, which are thought to enhance detection of courtship signals when reproduction is mostly likely to occur []. Similar patterns of seasonal auditory plasticity are observed in the plainfin midshipman fish (, here referred to as midshipman), a soniferous teleost fish native to the Pacific coast of North America. Like songbirds, midshipman rely on acoustic signaling for mate attraction and show hormonally mediated changes in auditory sensitivity that coincide with breeding status [–]. During the summer breeding season, large “Type I” male midshipman establish nests under intertidal rocks and produce low-frequency advertisement calls (“hums”) to attract gravid females for reproduction [–]. Playback experiments have shown that reproductive-state females are strongly attracted to these courtship hums, indicating that acoustic cues are a primary signal for mate detection and localization [,]. Neurophysiology studies demonstrate that key features of the male hum are encoded in the peripheral auditory system and that these encoding features are enhanced during the breeding season [–]. For example, reproductive females exhibit increased phase locking in the 8th cranial nerve, enabling more precise encoding of the periodicity in male hums []. Additionally, the auditory end organs of the inner ear, the saccule and the utricle, show seasonal shifts in auditory sensitivity, although no shift in auditory sensitivity has been observed within the lagena, an inner ear end organ that may be important for detecting higher intensity signals such as nearby conspecific vocalizations []. Specifically, auditory thresholds in the saccule and utricle are lower ( sensitivity is increased) in reproductive females compared to their non-reproductive counterparts [,]. These functional changes are supported by underlying morphological plasticity. The saccule of reproductive females contains a higher density of sound-transducing hair cells, a change not observed in the utricle or lagena []. This seasonal increase in hair cell density suggests that structural remodeling of the inner ear contributes to auditory enhancement. Together, these findings point to multiple mechanisms–neural, physiological, and cellular–that underlie reproductive state-dependent changes in auditory processing in the midshipman fish. However, the transcriptional mechanisms that regulate these seasonal changes remain largely unknown.