High sound pressure levels (SPL) pose notable risks in loud environments, particularly due to noise-induced hearing loss. Ill-fitting earplugs often lead to sound leakage, a phenomenon this study seeks to investigate. To validate our methodology, we first obtained computational and experimental acoustic transmission data for stand-alone slit resonators and orifices, for which extensive published data are readily available for comparison. We then examined the frequency-dependent acoustic power absorption coefficient and transmission loss (TL) across various leakage geometries, modeled using different orifice diameters. Experimental approaches spanned a frequency range of 1--5 kHz under SPL conditions of 120--150 dB. Key findings reveal that unsealed silicone rubber earplugs demonstrate an average TL reduction of approximately 18 dB at an overall incident SPL (OISPL) of 120 dB. Direct numerical simulations further highlight SPL-dependent acoustic dissipation mechanisms, showing the conversion of acoustic energy into vorticity in ill-fitting earplug models at an OISPL of 150 dB. These results highlight the role of earplug design for high-sound-pressure-level environments.
Whisphone is a novel earbud device designed for speech input via whispering. Utilizing canal-type earbuds with a unique microphone placement at the tip of the earplug, it effectively captures whispered voices radiated in the ear canal through bone conduction. This design can boost whispered voice volume with ear canal occlusion effect while simultaneously blocking external noise by sealing the ear hole. By incorporating Active Noise Canceling (ANC), Whisphone can effectively detect subtle whispers, even in noisy environments of up to 80dB(A). Its compact and comfortable design ensures discreet wearability, allowing users to interact with AI assistants hands-free without disturbing others in various daily situations such as offices, homes, or urban public spaces.
During the COVID-19 outbreak, the auscultation of heart and lung sounds has played an important role in the comprehensive diagnosis and real-time monitoring of confirmed cases. With clinicians wearing protective clothing in isolation wards, a potato chip tube stethoscope, which is a secure and flexible substitute for a conventional stethoscope, has been used in the first-line treatment of COVID-19 by Chinese medical workers. In this study, an optimal design for this simple cylindrical stethoscope is proposed based on the fundamental theory of acoustic waveguides. Analyses of the cut-off frequency, sound power transmission coefficient, and sound wave propagation in the uniform lossless tube provide theoretical guidance for selecting the geometric parameters for this simple cylindrical stethoscope. In addition, relevant suggestions about surface treatments for the inner wall as well as the use of noise-reduction earplugs are also part of this optimal design.
Scientists have identified LHAASO J1912+1014u as a cosmic accelerator that can push protons beyond one quadrillion electron volts。 The finding may help reveal where the Milky Way’s most energetic cosmic rays come from and how they influence the galaxy
A surprisingly simple change could make sodium-ion batteries far more powerful while opening the door to turning seawater into drinking water。 Researchers at the University of Surrey found that sodium vanadium oxide performs much better when its naturally occurring water is left inside instead of being removed during manufacturing
NASA’s Curiosity rover has entered a Martian valley covered by an astonishing “sea” of tiny polygon-shaped fractures。 The honeycomb patterns, each only a few inches wide, stretch across the landscape and even wrap around a nearby 20-foot-tall butte
A person’s sleeping brain may reveal warning signs of dementia long before memory problems begin。 Researchers used machine learning to analyze EEG recordings from about 7,000 adults and found that an older-than-expected “brain age” was tied to a sharply higher dementia risk。 Every additional 10 years of brain aging raised that risk by nearly 40%
Europa’s hidden ocean has made the icy moon one of the solar system’s most promising places to search for habitable conditions。 Scientists have hoped that water from this deep ocean might rise through cracks and form shallow reservoirs that future spacecraft could more easily study。 New simulations suggest that journey is unlikely because turbulent
Sweden could become an important source of rare earth elements needed for magnets and green technologies。 Instead of extracting one target metal, researchers are cataloging everything contained in Swedish mineral deposits。 They will then develop magnets using those naturally available combinations, potentially reducing pollution, waste, and relianc
The Backrooms began as a single eerie image of empty yellow rooms, but internet users transformed it into a vast fictional world that feels disturbingly real。 Through videos, games, maps, survival guides and social media stories, audiences do more than watch the horror unfold。 They help build and explore it
Scientists have successfully generated electricity with a hydrogen turbine that produces its own pressure through detonation waves instead of relying on a mechanical compressor。 The breakthrough could unlock dramatically more efficient power systems for clean energy and future aviation
A new 3D printing technique can produce exceptionally hard tungsten carbide cobalt while using less of its expensive raw materials。 By softening rather than fully melting the material, researchers created defect-free samples with industrial-grade hardness and opened the door to more efficient manufacturing
Rice University chemists have found a new way to make neodymium, a rare-earth metal, interact with oxygen。 Using a specially designed molecular structure described as a “basket,” the team positioned the atoms so they could form a bond once thought unlikely。 The breakthrough produced highly reactive compounds that could eventually give chemists alte
Scientists have created twisted laser beams that interact differently with right-handed and left-handed molecules, revealing their identity through the fragments they produce。 The approach could provide a faster, simpler, and more sensitive way to analyze important molecules used in chemistry and pharmaceuticals
Scientists have built the first all-optical photonic time crystal, allowing them to reshape the behavior of terahertz light at extraordinary speeds。 The breakthrough could open the door to ultrafast computing, smarter communication systems, advanced imaging, and a new generation of highly tunable lasers