There are many causes of (temporary) loss of hearing.
For example, when you have a cold. Your ears are connected to your throat and nose. If your nose is blocked, you often feel a pressure on your ears. This means that your eardrum is under pressure and cannot vibrate as well as usual, which in turn means you hear less.
More than half of people aged sixty years or older have some form of hearing impairment to varying degrees. This often goes unnoticed. People think you have the television volume turned up very high, for example, or that you think people are mumbling and you cannot understand them very well. It can also be that you do not hear so well because of medication you are taking. These are what are known as ototoxic medicines. In the Netherlands we have standard definitions for the extent of hearing impairment.
Watch the short film below to see that damage to the hearing and hearing impairment can be prevented: