Greyhound Racing Track Lure Systems—Acoustical Measurements Within and Adjacent to the Starting Boxes

This study investigates and compares the acoustic signatures of a traditional wire-cable-pulled lure system and two alternative battery-operated lure systems jointly developed by Covey Associates Pty. Ltd. and Steriline Pty. Ltd. to eliminate the hazardous steel-wire cable and make the sport of greyhound racing safer for greyhounds, participants and spectators. The acoustical measurements of these three lure systems were conducted at the Murray Bridge greyhound racing track. The lure sounds were measured by the high-frequency Brüel & Kjær (B&K) Type 4191 microphones for the 395 m and 455 m starts at two positions: within the starting box and on the track adjacent to the starting boxes. The measurements capture the sounds that the greyhounds hear before and after the opening of the starting box gate. The frequency-domain analysis and sound quality analysis were conducted to compare the lure sounds. It was found when the battery-lure was installed with all nylon rollers, it presented less sound energy and lower frequency than the traditional wire-cable-pulled lure. When two of the nylon rollers were replaced with steel rollers, the battery-operated lure emitted a louder and higher frequency sound than the traditional wire-cable-pulled lure. The different acoustic characteristics of these lure systems suggest future research is warranted on the reaction of greyhounds to different lure sounds, particularly their excitement level within the starting box as the lure approaches. This initial research also suggests some greyhounds may not clearly hear the battery-operated lure with all nylon rollers approaching the starting boxes and the timing of these greyhounds to jump may be delayed, particularly during high wind conditions.

Droplet lift-off from hydrophobic surfaces from impact with soft-hydrogel spheres

Droplet impacts on superhydrophobic surfaces may result in complete bouncing, with the absence of contact hysteresis and viscous dissipation leading the droplet to fully rebound off the surface. This rebound usually happens in the retraction phase, when the droplet retracts back after reaching a maximum spread diameter. Here, we present experimental evidence of a novel bouncing phenomenon where a sessile droplet on a hydrophobic surface bounces off the surface in its spreading phase when a soft deformable hydrogel sphere axisymmetrically impacts the droplet. We term this as 'Lift-Off' and propose a simple force balance based on the deformation characteristics of the hydrogel sphere to explain the out-of-plane jump of the droplet during spreading. We observe three different impact regimes, and propose their dependency on a modified elastic 'Mach' number (Ma*) with (Ma*)=0.2 corresponding to the onset of lift-off. We also report on the unique acoustic signatures of lift-off cases, associated with the capture of air-bubbles through the air-borne retracting droplet rim. Concerning the novel lift-off results, this work may have potential applications for drainage and surface cleaning, non-stick surface coating, industrial mixing and plant disease spreading.

Classification of Bladder Emptying Patterns by LSTM Neural Network Trained Using Acoustic Signatures

(1) Background: Non-invasive uroflowmetry is used in clinical practice for diagnosing lower urinary tract symptoms (LUTS) and the health status of a patient. To establish a smart system for measuring the flowrate during urination without any temporospatial constraints for patients with a urinary disorder, the acoustic signatures from the uroflow of patients being treated for LUTS at a tertiary hospital were utilized. (2) Methods: Uroflowmetry data were collected for construction and verification of a long short-term memory (LSTM) deep-learning algorithm. The initial sample size comprised 34 patients; 27 patients were included in the final analysis. Uroflow sounds generated from flow impacts on a structure were analyzed by loudness and roughness parameters. (3) Results: A similar signal pattern to the clinical urological measurements was observed and applied for health diagnosis. (4) Conclusions: Consistent flowrate values were obtained by applying the uroflow sound samples from the randomly selected patients to the constructed model for validation. The flowrate predicted using the acoustic signature accurately demonstrated actual physical characteristics. This could be used for developing a new smart flowmetry device applicable in everyday life with minimal constraints from settings and enable remote diagnosis of urinary system diseases by objective continuous measurements of bladder emptying function.

Units of processing in perceptual normalization for speaking rate

Because speaking rates are highly variable, listeners must use cues like phoneme or sentence duration to scale or normalize speech across different contexts. Scaling speech perception in this way allows listeners to distinguish between temporal contrasts, like voiced and voiceless stops, even at different speech speeds. It has long been assumed that this normalization or adjustment of speaking rate can occur over individual phonemes. However, phonemes are often undefined in running speech, so it is not clear that listeners can rely on them for normalization. To evaluate this, we isolate two potential processing units for speaking rate normalization---the phoneme and the syllable---by manipulating phoneme duration in order to cue speaking rate, while also holding syllable duration constant. In doing so, we show that changing the duration of phonemes both with unique acoustic signatures (/k\textscripta/) and overlapping acoustic signatures (/w\textsci/) results in a speaking rate normalization effect. These results suggest that even absent clear acoustic boundaries within syllables, listeners can normalize for rate differences on the basis of individual phonemes.

Sounding out falsified medicines from genuine medicines using Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS)

The trade in falsified medicine has increased significantly and it is estimated that global falsified sales have reached $100 billion in 2020. The EU Falsified Medicines Directive states that falsified medicines do not only reach patients through illegal routes but also via the legal supply chain. Falsified medicines can contain harmful ingredients. They can also contain too little or too much active ingredient or no active ingredient at all. BARDS (Broadband Acoustic Resonance Dissolution Spectroscopy) harnesses an acoustic phenomenon associated with the dissolution of a sample (tablet or powder). The resulting acoustic spectrum is unique and intrinsic to the sample and can be used as an identifier or signature profile. BARDS was evaluated in this study to determine whether a product is falsified or genuine in a rapid manner and at lower cost than many existing technologies. A range of genuine and falsified medicines, including falsified antimalarial tablets from south-east Asia, were tested, and compared to their counterpart genuine products. Significant differences between genuine and falsified doses were found in their acoustic signatures as they disintegrate and dissolve. Principal component analysis was employed to differentiate between the genuine and falsified medicines. This demonstrates that the tablets and capsules included here have intrinsic acoustic signatures which could be used to screen the quality of medicines.