The woes of aging seem to have made hearing loss an innate mechanism. We gradually lose hearing capabilities, as we grow older whereby the hurdle start for high–frequency sounds. The major solution to hearing loss is to increase the volume. It is a fact that elders who have fine hearing capabilities tend to experience some problems to process auditory, an example could be to identify a voice in a noise market place.
It is certain that loss of hearing related to aging encompasses more than simply the ear. Neurological degeneration associated to hearing loss is yet under-comprehended. At University of Rochester Medical Center in New York State, a new mouse model was used to enhance sciences understanding.
The research was led by Robert Frisina. The team has been using the mouse line that is called “CBA mice to study progressive hearing loss”. CBA mouse has the same effect like humans as they grow older, they lose high-frequency sound detection abilities. However, Firsina, decided to substitute CBA mice for C57 mice, which are well known for their bad hearing abilities. Yet, the C57 mice offsprings under the research had an exceptional outcome; they retained their hearing abilities to old age.
The team used an animal model that focused on identifying how the brain affected age-related hearing loss instead of the ear. A streamline of scientists suggest the effect to be caused by cognitive decline yet the complexity of the mammalian auditory system sets barriers to detect the cause-and-effect. The fact that age-related hearing loss is present at old age necessitates the evaluation an old ear and their respective neurological associations as younger mammalians do not have the problem.
Firsina’s father works at Rochester Institute of Technology, Robert Frisina, Sr., and he is also the director of hearing and speech research. Through clinical research, it had already been established that approximately 5 percent of adults above the age of 50 has what is referred to as the “golden ears”. They do actually detect frequencies human (20 hertz to 20 kilohertz) at an advanced age. According to Firsina, this new mouse line is similar to the golden ears of humans.
The hearing test used for mouse is alike the one used for newborn humans in hospitals. A series stimulated from a computer are played in the mice’s ears. The quantity of hair cells vibrating within the animal’s cochlease is thereby measured. Indirect hearing testing is also conducted via EEG-like recordings. The results for C57 mouse line was significantly better than for the CBA mice line at an advanced age which for mice is around 2 years.
The work on the Golden Ear Mice” is another research that has just set-off for Frisina and his colleagues. The genetic determinants of the so-called golden ear aspect must be detected. The genetics associated with deafness is well elaborated. Nonetheless genes related to age-related hearing loss remains under-evaluated according to Frisina.
At the University of Maryland, College Park, Sandra Gordon-Salant, a professor of audiology considers anatomical and cognitive studies on the C57 mice line as highly important. The new animal model can make it possible to evaluate cognition associated with hearing problems as well as other auditory processes. Advancing and finding the association of hearing loss with the neurological functions can better promote cures for hearing disabilities. New devices could be developed as well as possible pharmaceutical treatments to handle the hearing defects.
Research in the field of hearing loss is appealing to adults in the age range of 65 and above. Moreover, an increasing younger population is joining the cohorts as headphones and noise sources are triggering hearing loss at an early age.
Source Scientific America
Secondary Source: Science Daily
Wed, Jan 20, 2010
Bioscience, Health And Aging