32 THE HEARING REVIEW AUGUST 2004 reach the right ear a bit sooner than it will reach the left ear. It will also be slightly louder in the right than in the left ear. This head diffraction effect will enhance speech intelligibility in noise when speech and noise come from different sides of the head, because the brain can selectively attend to the ear with a better signal-to-noise ratio (SNR) f...

Until recently, noise suppression for telecommunications has been associated, almost exclusively, with corded and mobile phones. These small hand-held devices assumed particular use-cases; where voice generally entered from a microphone near the mouth, while an output stream exiting from the other end of the device reached only one ear. Over the years, the need for ambient noise suppression for...

Recently, hearing aid systems where the left and right ear devices collaborate with one another have received much attention. Apart from supporting natural binaural hearing, such systems hold great potential for improving the intelligibility of speech in the presence of noise through beamforming algorithms. Binaural beamforming for hearing aids requires an exchange of microphone signals between...

The CDC reported the results of two surveys of US hospitals conducted in 1992 and 1996 to determine the degree of implementation of the “CDC Guidelines for Preventing the Transmission of Mycobacterium tuberculosis at US Hospitals.” The 1992 survey included all public (city, county, Veterans’ Administration), and primary medical school-affiliated US hospitals (n=632) and a 20% random sample of a...

Introduction Elderly individuals with bilateral hearing loss often do not use hearing aids in both ears. Because of this, dichotic tests to assess hearing in this group may help identify peculiar degenerative processes of aging and hearing aid selection. Objective To evaluate dichotic hearing for a group of elderly hearing aid users who did not adapt to using binaural devices and to verify the ...

BACKGROUND Outbreaks of tuberculosis (TB) in hospitals have occurred when the Centers for Disease Control and Prevention (CDC) guideline recommendations for preventing the transmission of Mycobacterium tuberculosis were not fully implemented. OBJECTIVE To determine whether US hospitals are making progress in implementing the CDC guidelines for preventing TB. METHODS In 1992, we surveyed all...

UNLABELLED Carbon dioxide (CO2) rebreathing has been recognised as a concern regarding respirator use and is related to symptoms of discomfort, fatigue, dizziness, headache, muscular weakness and drowsiness. Previous investigations are limited by small sample size and have not evaluated the relationship between CO2 inhalation and phonic respiration (breathing during speech) in respiratory prote...

The inner ear can be permanently damaged by overexposure to high-level noise; however, damage can be decreased by previous exposure to moderate level, nontraumatic noise (). The mechanism of this "protective" effect is unclear, but a role for heat shock proteins has been suggested. The aim of the present study was to directly test protective effects of heat stress in the ear. For physiological ...