The eardrum is a highly sensitive membrane and nature has taken various precautions to protect it from damage:
Cerumen (earwax): The external part of the ear canal contains sweat and sebaceous glands. The glands produce a waxy substance known as cerumen or earwax, which traps bacteria and dust. Cerumen is only produced in the outer third of the ear canal where it can be removed. Never try to clean down inside of the canal yourself. If you have a problem, consult your hearing care professional or physician.
Protective hair: The external part of the ear canal is covered with tiny hairs that act like a curtain to protect the eardrum from dust and dirt. If dust or bacteria do succeed in penetrating the curtain they are trapped by the cerumen.
Ear canal: The eardrum is further protected by bends in the ear canal. This helps prevent objects accidentally entering the ear and damaging the eardrum.
Cerumen and hearing instruments: When you first start wearing a hearing instrument, it often seems like a foreign object in the ear. This feeling disappears after a short familiarization period. All the same, hearing instruments can stimulate the production of cerumen. Some instruments are equipped with a protective cerumen filter to help prevent earwax from entering the instrument. If the outlet of the hearing instrument is blocked by earwax, the volume may be reduced or even cut-off altogether.