While Road Rippers Lightning Rods, Let's Rock Elmo and the I Am T-Pain musical microphone might be sought-after gifts this holiday season, parents should ensure that their children don't risk permanent hearing damage by misusing them. Researchers from UC Irvine's Department of Otolaryngology measured the noise levels of two dozen popular toys in stores and purchased the 10 loudest for precise gauging in a soundproof booth at UC Irvine Medical Center. They found that all exceeded 90 decibels and several reached 100 or more, equivalent to the noise of a chain saw, subway train or power mower. "Generally, toys are safe if used properly, " said Dr. Hamid Djalilian, associate professor of otolaryngology and director of neurotology and skull base surgery. "We tested the sound levels at the speaker and again at 12 inches, which is about the length of a toddler's arm.
Nine out of 10 city dwellers may have enough harmful noise exposure to risk hearing loss, and most of that exposure comes from leisure activities. Historically, loud workplaces were blamed for harmful noise levels. But researchers at the University of Michigan found that noise from MP3 players and stereo use has eclipsed loud work environments, said Rick Neitzel, assistant professor in the U-M School of Public Health and the Risk Science Center. Robyn Gershon, a professor with the Philip R. Lee Institute for Health Policy Studies, University of California, San Francisco is the principal investigator on the study. This proved true even though MP3 player and stereo listening were just a small fraction of each person's total annual noise exposure. Neitzel said he was surprised by the findings.
According to an investigation published in Nature Neuroscience, individuals who suffer with hereditary DFNA2 hearing loss are more sensitive to low frequency vibration. Findings from the study reveal previously unknown associations between touch sensitivity and hearing loss. Specialized nerve cells in the skin are responsible for all sensations individuals feel when they touch - hot, cold, smooth, rough, pressure, pain, itch, vibrations, and more. The study was conducted by Professor Thomas Jentsch of the Leibniz-Institut fur Molekulare Pharmakologie (FMP)/Max Delbruck Center for Molecular Medicine (MDC) Berlin-Buch and Professor Gary Lewin (MDC), in collaboration with clinicians from the Netherlands, Madrid, Spain and Nijmegen. Several of the Spanish and Dutch family members who participated in the investigation suffer from hereditary DFNA2 hearing loss.
People with a certain form of inherited hearing loss have increased sensitivity to low frequency vibration, according to a study by Professor Thomas Jentsch of the Leibniz-Institut fĂ r Molekulare Pharmakologie (FMP)/Max DelbrĂ ck Center for Molecular Medicine (MDC) Berlin-Buch and Professor Gary Lewin (MDC), conducted in cooperation with clinicians from Madrid, Spain and Nijmegen, the Netherlands. The research findings, which were published in Nature Neuroscience *, reveal previously unknown relationships between hearing loss and touch sensitivity: In order to be able to 'feel', specialized cells in the skin must be tuned like instruments in an orchestra. The members of the Spanish and Dutch families who participated in the study were quite amazed when the researchers from Berlin unpacked their testing equipment.
"Imagine you are playing ping-pong with a friend. Your friend makes a serve. Information about where and when the ball hit the table is provided by both vision and hearing. Scientists have believed that each of the senses produces an estimate relevant for the task (in this example, about the location or time of the ball's impact) and then these votes get combined subconsciously according to rules that take into account which sense is more reliable. And this is how the senses interact in how we perceive the world. However, our findings show that the senses of hearing and vision can also interact at a more basic level, before they each even produce an estimate, " says Ladan Shams, a UCLA professor of psychology, and the senior author of a new study appearing in the December issue of Psychological Science, a journal published by the Association for Psychological Science.