Hearing Sounds Assignment Example | Topics and Well Written Essays - 500 words

Hearing Sounds - Assignment Example The outer ear is composed of three parts which are the pinna (or auricle), the external auditory canal (or external auditory meatus), and the tympanic membrane (or eardrum) (Net Industries and its Licensors ,par.2). The pinna is the organ on the side of our heads that we commonly call "the ear". The external auditory canal is a passageway in the temporal lobe of the skull that begins at the ear and extends inward and slightly upwards. The outer one-third portion of the canal is lined with a membrane containing ceruminous (ear wax producing) cells, and hair cells which protects the eardrum by trapping dirt and other foreign bodies. The purpose of the cerumen and hairs is to protect the eardrum by trapping dirt and to keep the canal moist. The tympanic membrane or eardrum is a thin, concave membrane stretched across the inner end of the external auditory canal and serves as a transmitter of sound by vibrating in response to sounds traveling down the external auditory canal, and beginni ng sound conduction in the middle ear. The middle ear starts from the inner surface of the eardrum. It is connected to a chain of three small bones called the ossicles, known as the malleus (hammer), incus (anvil) and stapes (stirrup). These bones conduct sound waves from the tympanic membrane to the inner ear.