The external ear is a protective funnel made up of the cartilaginous pinna, the external acoustic canal and the eardrum (Figure 9.12). The external acoustic canal is lined with small hairs and next to it lie the ceruminous glands, which produce cerumen, or ear wax. The amalgamation of cerumen and hairs help to prevent foreign objects from entering the ear.

The pinna collects sound waves and delivers them via the external acoustic canal to the tympanic membrane or eardrum, which vibrates in harmony (Millward [132]). The eardrum separates the external and middle ear; it has a slightly conical shape and the pointed end sits within the inner ear to assist the funnelling of sounds.

The middle ear is an air‐filled chamber. It contains the three smallest bones in the body: the malleus, incus and stapes, collectively known as the auditory ossicles. To one side, it has a thin bony partition that holds two small membrane‐covered apertures which are the oval and round windows (Tortora and Derrickson [228]). The auditory ossicles receive vibrations from the tympanic membrane. Vibrations are passed on to the oval window and through to the cochlea in the inner ear; within this process the sound waves are magnified (Balkany and Brown [14]).

At the bottom of the chamber lies the eustachian tube, which connects to the nasopharynx and regulates the pressure in the ear. It is usually closed but yawning or swallowing briefly opens it, allowing air to enter or leave until the pressure in the middle ear equalizes with the external air pressure (Balkany and Brown [14]). When the pressures are equalized, the tympanic membrane vibrates freely as the sound waves hit it. However, if the pressures are not balanced, the individual may experience pain, hearing impairment, tinnitus and/or vertigo (Tortora and Derrickson [228]).

The inner ear is very small and includes the organ of Corti (which is situated inside the snail‐shaped cochlea), the three semi‐circular canals and the vestibular apparatus (Figure 9.12) and is the organ for hearing. It is filled with fluid and has a membranous layer that connects to the end of the auditory nerve; the membrane is covered in tiny cells with hair‐like projections (Eggermont [55]). Sound waves travel through the fluid and are distributed to the hair cells. At this point, the sound waves change to impulses, which pass along the auditory nerve to the brainstem and cortex, where they are interpreted as sound.

The semi‐circular canals and vestibular apparatus maintain balance. These canals are highly sensitive; they contain fluid and hair cells that recognize when the head moves and send signals to the brain to maintain equilibrium. The brain interprets these messages along with visual input from the eyes (Balkany and Brown [14]). Adjustments to the muscles and joints are made in response to the information received (Balkany and Brown [14], Tortora and Derrickson [228]).

Disorders of the inner ear structures can lead to the patient developing symptoms of vertigo or hearing loss (Balkany and Brown [14]). Vertigo is a sensation of the environment around the patient moving or spinning; other potential symptoms include loss of balance, feeling sick or being sick, and dizziness (NHS Inform Scotland [148]).

Ear wax (cerumen) is a waxy secretion from glands within the auditory canal, combined with skin scales and hair. As the cerumen dries, it usually falls out of the ear canal but in some circumstances the wax can become impacted (Schwartz et al. [205]). A build‐up of wax is more likely to occur in older adults and patients who use hearing aids, people with learning difficulties, people who have a narrow exterior auditory meatus and people who insert implements into the ear (RPECCAS [202]) (Box 9.4). Communication and balance can be affected by poor ear hygiene; for example, using cotton buds to clean the ears can result in ear wax impaction, which can dull hearing.

Cerumen impaction occurs in up to 6% of the general population, affecting 10% of children and over 30% of the elderly and cognitively impaired populations (Sevy and Singh [208]). Excessive wax should be removed before it becomes impacted, to avoid symptoms of ear wax impaction. The symptoms of ear wax impaction are: