Exposure to a noise level of 90 decibels may result in what risk for humans?

Exposure to a noise level of 90 decibels poses a significant risk for humans, primarily leading to hearing damage. At this level, sound is loud enough to potentially cause both temporary threshold shifts in hearing and, with prolonged exposure, more permanent damage. The human ear is not designed to handle such intense noise for extended durations, and this can damage the hair cells in the cochlea, which play a crucial role in the auditory process.

As for the other options: hearing improvement is unlikely as loud noise typically has a detrimental effect rather than enhancing hearing. Temporary hearing loss can occur, but it is typically a precursor or a symptom of the actual hearing damage that can develop from consistent exposure to high decibel levels. Increased auditory sensitivity is also not a consequence of exposure to harmful noise levels but rather an indication of healthy hearing capabilities. Therefore, understanding the risks associated with prolonged exposure to noise at this level helps emphasize the importance of hearing protection in environments where such conditions are present.