There are generally three types of hearing loss, and they occur for different reasons. Sensorineural hearing loss occurs when the tiny hair cells in the inner ear become damaged. This can occur in older people, but also for people who have been exposed for a high level of noise for a prolonged period of time.
Many people experience conductive hearing loss. This occurs when there is a blockage between the outer ear, the middle ear, and/or the middle ear. When this happens, sound waves cannot effectively travel, and louder sounds become muffled and softer sounds can be imperceptible altogether.
Mixed hearing loss occurs when there are problems conducting sound to the inner ear, but when the inner ear’s hair cells are also damaged. It is “mixed” because it is a combination of conductive and sensorineural hearing loss.
Sometimes the brain has difficulty processing the very information contained in sound: where sounds are coming from, distinguishing one sound from the next, or making sense of how sounds are ordered (such as finding it hard to block out background noise to understand a conversation). This type of hearing loss can be broadly categorized as an auditory processing disorder.