This study presents a methodology for measuring and modelling honey bee sound power levels to evaluate the placement and feasibility of acoustic monitoring hardware. In-vitro measurements established that both worker bees and drones produce peak acoustic energy around the 200 Hz 1/3 octave band, with drones generating higher mean A-weighted sound power levels (33.1 ± 8.1 dB) than workers (27.8 ± 2.3 dB). Combining in-situ colony measurements with Finite Element Method directivity modelling of a Warsaw-type beehive, the custom BeeEar simulation platform was developed to project sound pressure levels across large bee populations. Simulation of a 25,500-bee swarm demonstrated a peak SPL of 52.9 dB(A) at the swarm centre. Under typical ambient noise, reliable swarm detection required microphone placement within 6 m of the swarm centre. However, low-cost digital MEMS microphones were shown to be feasible, offering an effective monitoring radius of 20 to 25 m when constrained primarily by sensor noise floor.
The article presents a room acoustics study conducted for a multi-purpose hall, which is currently in the design phase. The hall is part of the Cultural Center building, which will be constructed in Zagórz, a small town located in the southern part of Poland in the Podkarpacie region. The architectural design was developed by Studio Święciński Architekci, based in Krosno. The results of the acoustic prediction for the hall were obtained using the open-source software I-SIMPA. To perform the acoustic study, the multi-purpose hall was geometrically modeled as a 3D shape in acoustical scale; sound absorption and scattering coefficients for the internal surfaces were then assigned along with the sound source and receivers in the audience area. Several acoustic parameters (T_Sabine, T_Eyring, T30, EDT, C80, D50, G, STI) were calculated in pre and post-treatment conditions, to simulate the acoustic efficiency of the conference hall in accordance with its future use.
The ultrasound waves are recognized as an effective green technology with outstanding potentials in various applications including the dehydration processes of food materials. However, the application of this technology is still confined at the laboratory levels due to limited power capacity of available ultrasound systems in the large-scale airborne applications. The extensive plate radiators are essential parts that can effectively increase the amplitude of oscillations generated by piezo-electric transducers and induce high-intensity acoustic pressure field in the surrounding airflow. Using an analytical model, the geometric parameters in a simple flat circular radiator were evaluated. However, this configuration propagated counter-phase radiations with diminished overall ultrasound effect. In this study, a stepped profile with specific geometrical dimensions is proposed to modify the response of excited extensive plate. The modal analysis showed that for 20,259 Hz, just close to the system’s resonance frequency, the plate generated directed and focused vibrations. Furthermore, the design provided a more convenient distribution of natural frequencies to eliminate the risk of harmful interaction of mode shapes.
This work mainly focuses on a deepwater soundscape study in the Nansen Basin, Central Arctic Ocean, by using Ambient Noise Measurement System (ANMS) data, which was deployed as part of the Nansen Environmental and Remote Sensing Center (NERSC-4) mooring from September 2019 to July 2020. The main objective of the work is to study the sources of underwater noise of the Central Arctic Ocean (CAO) along with their characteristic patterns. Also in this work, the seasonal variation of the sound pressure level of CAO is studied. The seasonal variation of the sound pressure level of the CAO is maximum in summer, and the minimum seasonal variation was observed during spring. The difference in seasonal variability in 1/3 octave band frequencies between summer and spring was 4.1 dB (re 1 μPa²/Hz). Shipping and marine species are the most dominant noise sources of the Central Arctic Ocean. Bowhead whales and bearded seals are the most common marine species observed in this location. The bearded seal vocalisation is more intense between 300 and 700 Hz. Bowhead whales produce two different types of simple calls i.e., sound patterns : one is S-moans, and the other is V-moans. The S-moan patterns are mainlydominated by low frequencies i.e., below 600 Hz. The V-moans patterns are dominated in the frequency range of 300 to 1230 Hz. The killer whales are also observed in the study location, which represents a shifting Arctic environment. The soundscape generated by killer whales is observed between 160 Hz and 2 kHz.
In recent years, virtual reality (VR) has been an attractive alternative to traditional methods of conducting hearing tests, offering both a natural way to indicate sound direction and complete digital data recording. The aim of this study was to analyze how the use of VR goggles and motion controllers affects the accuracy of localizing acoustic stimuli and the subjective comfort of participants, compared to a WEB-based application operated with a mouse. The study was performed for 16 azimuthal samples (0° elevation) and 8 elevation samples at azimuth 90°. Mean absolute angular errors (MAAE) were analyzed, and the paired-samples t-tests were performed. The results show that using the VR interface can reduce horizontal MAAE by 7° compared to the WEB-based interface. In the elevation tasks, no statistically significant differences were observed. Respondents rated VR the highest in terms of intuitiveness, comfort, speed, and perceived precision. These findings confirm the potential of VR to be used in localization tests, especially in the horizontal plane, and suggest directions for further research on HRTF personalization and interface optimization for elevation tasks.
