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Aspirin-Induced Hearing Loss
Although it is known that high doses of aspirin can cause ulcers and temporary deafness, the responsible biochemical mechanism has not been deciphered. A study published in the September issue of Biophysical Journal may shed some light.
The research from Rice University shows how salicylate-an active metabolite of aspirin-weakens lipid membranes. Researchers believe these mechanical changes disrupt the lining of the stomach. By a similar mechanism, the changes may result in aspirin-related deafness by interfering with the proper function of prestin, a transmembrane protein that's critical for mammalian hearing.
First identified five years ago, prestin is a transmembrane protein found in the inner ear. A motor protein, prestin is thought to act like a piezocrystal, converting electrical signals into mechanical motion. In the outer hair cells of the cochlea, prestin acts as a molecular motor, causing the cells to move rhythmically and amplify the sounds we hear.
Scientists Develop Ear Implants
Scottish scientists are recreating ossicular bones in the middle ear to build a device that could restore the hearing of millions of people with hearing loss.
The device called SMARTFIT is still in development by bio-engineers at Dundee University, but doctors say it might help people whose middle ear has been damaged by an infection.
Robert Mills, a consultant ear surgeon at Edinburgh University, said current prosthetic middle ears are rigid devices based on the simple ear of a bird. The new design will be a more complex spring mechanism like the human ear that can cope with changes in pressure.
The scientists are developing the device in the laboratory using human temporal bones and hope to see it in use within 10 years.
Men Can't Hear Women
A new study published in NeuroImage reports that men have problems hearing women's voices because of differences in the way the brain responds to male and female voices. The researchers at Sheffield University in northern England say that the female voice is more complex than the male voice, because of differences in the size and shape of the vocal cords and larynx between men and women. In addition, women have a greater natural "melody" in their voices, which creates a more complex range of sound frequencies than in a male voice.
One of the researchers, Michael Hunter, said that when men hear a female voice, the auditory section of the brain is activated, which analyzes the different sounds in order to "read" the voice and determine the auditory face.
The study determined that men hear female voices using the auditory part of the brain that processes music, while male voices engaged a simpler mechanism.
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