Hearing loss is the most frequent sensorial impairment in the world, especially in low and middle income countries. Almost 5% of the world population (360 million people) is affected by hearing loss. Hearing deficits are highly prevalent among older adults and are associated with declines in cognitive, physical, and mental health, especially in the geriatric population. Trauma situations, such as barotrauma and head trauma, can also lead to temporary or permanent conductive or sensorineural hearing loss, which can lead to quality of life impairment. This book provides new research in the etiology, management and societal implications of hearing loss.