For example, poor hearing is often caused by several infections. These infections or diseases may damage part of the hearing system during childhood. Head colds, tonsillitis, measles, scarlet fever, mumps and meningitis are some causes or diseases which may bring on poor hearing.
A less common cause of poor hearing is a bony growth in the ear. These growths make it difficult for the sound wave to be conducted into the ear. The sound of loud explosions or violent vibrations of sound are also quite responsible for poor hearing.