Abstract:
The mechanism of hearing is a complex biological process. In humans, a number of genes
are known to underlie this process. Understanding of these genes in auditory physiology is
providing substantial information regarding biological aspects of the normal process of
hearing and its impairment. In the last 10 years or so, advances in the area of human
genetics and cell biology have provided major insights into the mechanisms involved in the
development, function and dysfunction of the cochlea, the auditory signal transduction
apparatus in humans. The progress in identifying genes involved in hearing impairment has
been remarkable in the recent years. This is evident from the fact that in the last ten years or
so, mutations in 46 different genes have been implicated in human NSHL (Friedman and
Griffith 2003, Hilgert et al. 2008). Before human genome sequence became available, about
13 genes had been identified for human nonsyndromic hearing loss, whereas after the
availability of human genome sequence in the year 2000, 33 additional genes have been
identified. Information about these genes is revolutionizing our knowledge of the molecular
processes involved in hearing and their alteration leading to hearing loss. Although there is
a significant progress in understanding the genetic aspects of hereditary hearing loss, it is
clear that more genes and mutations await discovery.