There is an increased awareness of how the quality of the acoustic environment impacts the lives of human beings. Several studies have shown that sound pollution has adverse effects on many populations, from infants to adults, in different environments and workplaces. Hospitals are susceptible environments that require special attention since sound can aggravate patients' health issues and negatively impact the performance of healthcare professionals. This paper focuses on Neonatal Intensive Care Units (NICU) as an especially sensitive case representing a hostile acoustic environment in which healthcare professionals have little awareness of how unwanted sounds impact the perceived quality of the soundscape. We performed a semi-systematic review of scientific literature on sound assessment studies in NICU from 2001. A thematic analysis was performed to identify emerging themes that informed the analysis of 27 technological solutions for the assessment of sound quality in indoor and outdoor environments. Solutions were categorized by functions and evaluation methods and grouped according to the characteristics of the design components, i.e., acquisition, computation, and communication strategies. Results highlight a lack of solutions to assess the qualitative characteristics of indoor environments such as NICU and forecast the footprint that different sound sources have on the indoor soundscape. Such solutions are urgently needed to empower healthcare professionals, and especially nurses, to actively modify and prevent the negative impact of unwanted sounds on NICU and critical care soundscape.@en

Good sleep is conducive to the recovery process of hospital patients - and yet, in many wards, sleep duration and quality can often be suboptimal, in part due to modifiable hospital-related sounds and noises. At the neurological ward of the Reinier de Graaf hospital in Delft, the Netherlands, we developed and evaluated a prototype information exchange system to raise awareness of specific sounds as disturbing patients' sleep. The system both classifies different relevant sound events and tracks sleep quality (using a Fitbit device). This information is then visualized for patients and staff to present the influence of the soundscape on patients' sleep hygiene in a friendly and comprehensive way. We discuss the design process, including a context study and various evaluations of the technology, interface, and created affordances. Our initial findings indicate that visualizing hospital soundscapes may, indeed, support both patients and staff in their efforts towards better sleep hygiene.

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Inside the Neonatal Intensive Care Unit (NICU), exposure to loud sounds such as acoustic medical alarms can have adverse effects on neonates, parents, and medical staff. With the aim of having an accurate overview of which and how often acoustic medical alarms occur, this paper presents a simple signal processing-based approach for detecting and recognizing automatically and permanently patient monitoring alarms inside the NICU. The proposed algorithm leverages from prior knowledge of the spectro-temporal structures of alarms to first detect each single occurrence of an alarm tone, and then group the detected tones into a known alarm pattern. A preliminary evaluation of the algorithm on a small set of 4-channel recordings capturing a simulated NICU soundscape shows that around 99% of the acoustic alarms are correctly recognized, and that around 99% of the recognized alarms are true alarms. The algorithm lends itself to efficient real-time implementation and to generalization to other alarm patterns as defined by the IEC 60601-1-8 standard.

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While previous research on spatial sound perception investigated the physical mechanisms producing the most relevant elevation cues, how spectral notches are generated and related to the individual morphology of the human pinna is still a topic of debate. Correctly modeling these important elevation cues, and in particular the lowest frequency notches, is an essential step for individualizing Head-Related Transfer Functions (HRTFs). In this paper we propose a simple computational model able to predict the center frequencies of pinna notches from ear meshes. We apply such a model to a highly controlled HRTF dataset built with the specific purpose of understanding the contribution of the pinna to the HRTF. Results show that the computational model is able to approximate the lowest frequency notch with improved accuracy with respect to other state-of-the-art methods. By contrast, the model fails to predict higher-order pinna notches correctly. The proposed approximation supplements understanding of the morphology involved in generating spectral notches in experimental HRTFs.

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We present a hybrid approach to individualized head-related transfer function (HRTF) modeling which requires only 3 anthropometric measurements and an image of the pinna. A prediction algorithm based on variational autoencoders synthesizes a pinna-related response from the image, which is used to filter a measured head-andtorso response. The interaural time difference is then manipulated to match that of the HUTUBS dataset subject minimizing the predicted localization error. The results are evaluated using spectral distortion and an auditory localization model. While the latter is inconclusive regarding the efficacy of the structural model, the former metric shows promising results with encoding HRTFs. Index Terms: Hardware - Digital signal processing; Computing methodologies - Neural networks; Applied computing - Sound and music computing

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Previous research stresses the importance of Head-Related Transfer Function (HRTF) individualization approaches for accurately locating sound sources in virtual 3D spaces. However, in the realm of interactive experiences, methods for assessing whether individualized HRTFs bring a benefit to the player experience are rarely investigated. Methods to improve spatial audio rendering are needed now than ever since Virtual Reality (VR) is becoming a mainstream technology for interactive experiences. This paper proposes a method of using in-game metrics to test the hypothesis that individualized HRTFs improve the experience of both expert and novice players in a First-Person Shooter (FPS) game on a desktop environment. The FPS game provides players with a localization task across three different audio renderings using the same acoustic spaces: stereo panning (control condition), generic binaural rendering, and individualized binaural rendering. Collected metrics from the game include localization error, spatial quality attributes, and an extensive questionnaire. The individualized HRTFs for each participant were synthesized using a hybrid structural model. The model employs a deep learning architecture to synthesize a pinna-related response from a pinna image, and combines it with a measured generic head-and-torso response. The interaural time difference (ITD) is then adjusted to match that of an HRTF dataset subject minimizing a localization error metric. The results show that the 22 participants performed significantly better in the localization task with their individualized HRTF. Increased localization accuracy with respect to the generic HRTF was recorded both in azimuth and elevation perception, and especially in the case of expert game players.@en