A mystery solved: human high-frequency middle-ear motion.

The middle ear transforms sound from low-impedance external air to high-impedance cochlear fluid. However, the human stapes - the input to the cochlea - has been reported to have minimal or no motion above ~ 4 kHz. For decades, this lack of observed high-frequency stapes motion has been puzzling, as it is inconsistent with our ability to hear up to 20 kHz.

The impact of size on middle-ear sound transmission in elephants, the largest terrestrial mammal.

Elephants have a unique auditory system that is larger than any other terrestrial mammal. To quantify the impact of larger middle ear (ME) structures, we measured 3D ossicular motion and ME sound transmission in cadaveric temporal bones from both African and Asian elephants in response to air-conducted (AC) tonal pressure stimuli presented in the ear canal (PEC). Results were compared to similar measurements in humans.

Pediatric capacity crisis: A framework and strategies to prepare for a pediatric surge.

A pediatric capacity crisis developed across the country in the Fall and Winter of 2022 due to a combination of factors, including a surge in respiratory viruses, staffing shortages, and historical closures of inpatient pediatric units. The COVID-19 pandemic and associated surge in critically ill adult patients demonstrated that health care systems and health care workers can quickly implement creative and collaborative system-wide solutions to deliver the best care possible during a capacity crisis. Similar solutions are needed to respond to future surges in pediatric volume and to maintain a high standard of care during such a surge.

Measurements of bone-conducted sound in the chinchilla external ear.

We measure bone-conduction (BC) induced skull velocity, sound pressure at the tympanic membrane (TM) and inner-ear compound-action potentials (CAP) before and after manipulating the ear canal, ossicles, and the jaw to investigate the generation of BC induced ear-canal sound pressures and their contribution to inner-ear BC response in the ears of chinchillas. These measurements suggest that in chinchilla: i.) Vibrations of the bony ear canal walls contribute significantly to BC-induced ear canal sound pressures, as occluding the ear canal at the bone-cartilaginous border causes a 10 dB increase in sound pressure at the TM (P) at frequencies below 2 kHz.

The impact of size on middle-ear sound transmission in elephants, the largest terrestrial mammal.

Elephants have a unique auditory system that is larger than any other terrestrial mammal. To quantify the impact of larger middle ear (ME) structures, we measured 3D ossicular motion and ME sound transmission in cadaveric temporal bones from both African and Asian elephants in response to air-conducted (AC) tonal pressure stimuli presented in the ear canal (P ). Results were compared to similar measurements in humans.