If both air conduction and bone conduction thresholds show the same degree of hearing loss, it is called sensory hearing loss. Sensory hearing loss can be caused by aging or by exposure to excessive noise over long periods of time. This can happen to young people who play loud music all day and night, or to people who work with loud machinery. Young people can avoid it by keeping the music down, while people who work with loud machinery wear earguards.
The diagram below left shows a normal audiogram and the diagram below left shows a typical audiogram from a case of sensory hearing loss (both audiograms are for the left ear).