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Preschool children are regularly exposed to high noise levels that may affect hearing. A previous study has linked preschool noise exposure to reduced distortion product otoacoustic emission (DPOAE) amplitudes. Since DPOAEs primarily reflect outer hair cell (OHC) activity, they provide an indirect marker of cochlear function. Measurement accuracy can be affected by middle-ear pressure. Pressurised DPOAEs (pDPOAEs) compensate for middle-ear pressure during recording. This cross-sectional study aimed to examine the relationship between preschool noise exposure and pDPOAE amplitudes while accounting for middle-ear pressure. Seventy-five children (4-6 years old) were monitored using dosimeters to measure the equivalent continuous sound level (LAeqTi) and the 95th percentile of maximum levels (LAFmax,95). Of these, 56 children completed pDPOAE testing at four time points during the preschool week. Linear mixed-effects models evaluated associations with noise exposure, time of day and progression across the week. For personal dosimetry, the mean LAeqTi was 80 dB (range: 60-98 dB) and the mean LAFmax,95 was 97 dB (range: 77-110 dB). Most LAeqTi levels (86.2%) were between 75-85 dB, with LAFmax levels exceeding 115 dB in 53.8% of the cases. No significant associations were found between LAeqTi or LAFmax,95 and pDPOAE amplitudes (p > 0.05). Time-of-day differences were observed, with higher amplitudes in the afternoon at 4 kHz (p = 0.045) and 6 kHz (p = 0.047) in the right ear, and 3 kHz in the left ear (p = 0.021). Girls showed higher amplitudes than boys at 4 kHz in the left ear (p = 0.030). Although pDPOAE amplitudes varied with time of day, and sex, a direct exposure-response relationship with preschool noise was not demonstrated. Short-term variations in typical preschool noise exposure may not measurably affect cochlear function in young children. Future research should refine exposure assessment and recording protocols to reduce variability and improve detection of small physiological changes.

\"The negative environmental effects of media culture are not often acknowledged: the fuel required to keep huge server farms in operation, landfills full of high tech junk, and the extraction of rare minerals for devices reliant on them are just some of the hidden costs of the contemporary mediascape. Eco-Sonic Media brings an ecological critique to the history of sound media technologies in order to amplify the environmental undertones in sound studies and turn up the audio in discussions of greening the media. By looking at early and neglected forms of sound technology, Jacob Smith seeks to create a revisionist, ecologically aware history of sound media. Delving into the history of pre-electronic media like hand-cranked gramophones, comparatively eco-friendly media artifacts such as the shellac discs that preceded the use of petroleum-based vinyl, early forms of portable technology like divining rods, and even the use of songbirds as domestic music machines, Smith builds a scaffolding of historical case studies to demonstrate how 'green media archaeology' can make sound studies vibrate at an ecological frequency while opening the ears of eco-criticism. Throughout this eye-opening and timely book he makes readers more aware of the costs and consequences of their personal media consumption by prompting comparisons with non-digital, non-electronic technologies and by offering different ways in which sound media can become eco-sonic media. In the process, he forges interdisciplinary connections, opens new avenues of research, and poses fresh theoretical questions for scholars and students of media, sound studies, and contemporary environmental history\"-- Provided by publisher.

Automatic monitoring of biodiversity by acoustic sensors has become an indispensable tool to assess environmental stress at an early stage. Due to the difficulty in recognizing the Amazon's high acoustic diversity and the large amounts of raw audio data recorded by the sensors, the labeling and manual inspection of this data is not feasible. Therefore, we propose an ecoacoustic index that allows us to quantify the complexity of an audio segment and correlate this measure with the biodiversity of the soundscape. The approach uses unsupervised methods to avoid the problem of labeling each species individually. The proposed index, named the Ecoacoustic Global Complexity Index (EGCI), makes use of Entropy, Divergence and Statistical Complexity. A distinguishing feature of this index is the mapping of each audio segment, including those of varied lengths, as a single point in a 2D-plane, supporting us in understanding the ecoacoustic dynamics of the rainforest. The main results show a regularity in the ecoacoustic richness of a floodplain, considering different temporal granularities, be it between hours of the day or between consecutive days of the monitoring program. We observed that this regularity does a good job of characterizing the soundscape of the environmental protection area of Mamirauá, in the Amazon, differentiating between species richness and environmental phenomena.

Despite hosting some of the highest concentrations of biodiversity and providing invaluable goods and services in the oceans, coral reefs are under threat from global change and other local human impacts. Changes in living ecosystems often induce changes in their acoustic characteristics, but despite recent efforts in passive acoustic monitoring of coral reefs, rapid measurement and identification of changes in their soundscapes remains a challenge. Here we present the new open-source software CoralSoundExplorer , which is designed to study and monitor coral reef soundscapes. CoralSoundExplorer uses machine learning approaches and is designed to eliminate the need to extract conventional acoustic indices. To demonstrate CoralSoundExplorer ’s functionalities, we use and analyze a set of recordings from three coral reef sites, each with different purposes (undisturbed site, tourist site and boat site), located on the island of Bora-Bora in French Polynesia. We explain the CoralSoundExplorer analysis workflow, from raw sounds to ecological results, detailing and justifying each processing step. We detail the software settings, the graphical representations used for visual exploration of soundscapes and their temporal dynamics, along with the analysis methods and metrics proposed. We demonstrate that CoralSoundExplorer is a powerful tool for identifying disturbances affecting coral reef soundscapes, combining visualizations of the spatio-temporal distribution of sound recordings with new quantification methods to characterize soundscapes at different temporal scales.

The literature on sound production behaviours in fish in the wild is quite sparse. In several taxa, associations between different sound types and given behaviours have been reported. In the Holocentridae, past nomenclature of the different sound types (knocks, growls, grunts, staccatos and thumps) has been confusing because it relies on the use of several terms that are not always based on fine descriptions. Our study aims to ascertain whether holocentrids can produce a variety of sounds in the wild and if these sounds are associated with specific behaviours. Additionally, we aim to determine whether sounds produced by hand-held specimens, a common methodology to record sounds in standardised conditions in fishes, could correspond to some sounds produced by free-swimming individuals in natural conditions. Our study shows that all holocentrid species are able to produce sounds in 6 behavioural contexts of both agonistic (conspecific and heterospecific chases, competition) and social signalling types (acceleration, broadcasting, body quivering), in addition to previously described mobbing towards moray eels and symbiotic interactions with cleaner wrasses. In holocentrids, acoustic communication is not only based on single calls but can also involve series of sounds of different types that are arranged randomly. The large amount of combinations within acoustical events for each behaviour, resulting from both the quantity of sounds and their diversity, supports the absence of stereotypy. This suggests that sounds are produced to reinforce visual communication during the day in this family. Our results also suggest that sounds recorded by hand-held fishes are produced naturally in the wild. Our study challenges past nomenclatures and demonstrates sound critical function in augmenting visual communication, advancing our comprehension of acoustic ecology in teleost species.

Background Menstrual hygiene practices among visually impaired young girls are a significant public health concern in Rwanda. Limited knowledge about menstruation leads to inadequate hygiene practices, increasing the risk of cervical cancer, urinary tract infections, and reduced quality of life. The menstrual hygiene needs of visually impaired girls who depend on daily assistance for personal hygiene have not been adequately addressed in previous studies. Objectives To assess the effect of an audio-recorded program on the knowledge and self-reported practices of menstruation hygiene among visually impaired young girls in Rwanda. Methodology A pre-post mixed intervention study was conducted involving 93 visually impaired young girls from four specialized educational institutions. After obtaining consent and assent, baseline data were collected following an audio-recorded intervention. A pretested tool was used to measure participants’ knowledge and practices about menstruation and menstrual hygiene. Post-interventional data was collected, and paired t-tests were used to analyze changes in knowledge and practice scores. Qualitatively, focus group discussions were used to evaluate the perceived effect of the audio-recorded program. Qualitative data were organized by Dodoose software and analyzed using thematic analysis. Results The majority of participants (67.7%) were enrolled in secondary education level and lived in rural areas (76.3%), with the largest proportion (43%) being between the ages of 16 and 20 years. There was a significant increase in the knowledge of young visually impaired girls ( p  < 0.001) after the audio-recorded intervention program. There was a significant increase in the overall menstrual hygiene practice after the implementation of the audio-recorded program ( p  < 0.001). Qualitatively, four themes emerged from the study, including improved knowledge and abilities, boosted confidence, the convenience of audio, and the perceived need to increase audio effectiveness. Conclusion The study revealed a significant association between the audio-recorded interventions and improved menstrual hygiene knowledge and practices among visually impaired young girls. However, since the study utilized a pretest-posttest design, a randomized controlled trial is recommended for robust evidence.

We determined the relationship between acoustic diversity and metrics of vertical forest structure derived from light detection and ranging (LIDAR) data in a neotropical rainforest in Costa Rica. We then used the LIDAR-derived metrics to predict acoustic diversity across the forest landscape. Sound recordings were obtained from 14 sites for six consecutive days during dusk chorus (6 pm). Acoustic diversity was calculated for each day as the total intensity across acoustic frequency bands using the Shannon index and then averaged over the 6 days at each site. A 10 m radius around each site was used to obtain several LIDAR-derived metrics describing the vertical structural attributes of the forest canopy. Multiple linear regression (MLR) with Akaike information criterion was used to determine a top-ranked model with acoustic diversity as the dependent variable and the LIDAR metrics as independent variables. Acoustic diversity was modeled for forested areas (where canopy height was >20 m) at 20 m resolution using coefficients obtained from the MLR, and a hotspot analysis was conducted on the resulting layer. Acoustic diversity was strongly correlated ( R 2  = 0.75) with the LIDAR metrics suggesting that LIDAR-derived metrics can be used to determine canopy structural attributes important to vocal fauna species. The hotspot analysis revealed that the spatial distribution of these canopy structural attributes across the La Selva forest is not random. Our approach can be used to identify forest patches of potentially high acoustic diversity for conservation or management purposes.

Acoustic monitoring has been tested as an alternative to the traditional, human-based approach of surveying birds, however studies examining the effectiveness of different acoustic methods sometimes yield inconsistent results. In this study we examined whether bird biodiversity estimated by traditional surveys of birds differs to that obtained through soundscape surveys in meadow habitats that are of special agricultural importance, and whether acoustic monitoring can deliver reliable indicators of meadows and farmland bird biodiversity. We recorded soundscape and simultaneously surveyed birds by highly skilled human-observers within a fixed (50 m and 100 m) and unlimited radius using the point-count method twice in the breeding season at 74 recording sites located in meadows, in order to compare differences in (1) bird biodiversity estimation of meadow, farmland, songbird, and all bird species and (2) the detection rate of single bird species by these two methods. We found that recorders detected more species in comparison to the human-observers who surveyed birds within a fixed radius (50 and 100 m) and fewer when detection distance for human-observers was unlimited. We did not find significant differences in the number of meadow and farmland bird species detected by recorders and observers within a 100 m radius–the most often used fixed radius in traditional human based point-counts. We also showed how detection rate of 48 the most common bird species in our study differ between these two methods. Our study showed that an acoustic survey is equally effective as human observers surveying birds within a 100 m radius in estimation of farmland and meadow bird biodiversity. These groups of species are important for agricultural landscape and commonly used as indicators of habitat quality and its changes. Even though recorders rarely detect species that remain mostly silent during the observation periods, or species that are further distant than 100 m away, we recommend using acoustic soundscape recording methods as an equally effective and more easily standardised alternative for monitoring of farmland and meadow bird biodiversity. We propose adaptation of acoustic approach to long-term, large-scale monitoring by collecting acoustic data by non-specialists, including landowners and volunteers, and analysing them in a standardised way by units supervising monitoring of agriculture landscape.

Anthropogenic noise in the ocean has increased substantially in recent decades, and motorized vessels produce what is likely the most common form of underwater noise pollution. Noise has the potential to induce physiological stress in marine fishes, which may have negative ecological consequences. In this study, physiological effects of increased noise (playback of boat noise recorded in the field) on a coastal marine fish (the giant kelpfish, Heterostichus rostratus) were investigated by measuring the stress responses (cortisol concentration) of fish to increased noise of various temporal dynamics and noise levels. Giant kelpfish exhibited acute stress responses when exposed to intermittent noise, but not to continuous noise or control conditions (playback of recorded natural ambient sound). These results suggest that variability in the acoustic environment may be more important than the period of noise exposure for inducing stress in a marine fish, and provide information regarding noise levels at which physiological responses occur.