BASIC OVERVIEW OF THE EAR AND HEARING LOSS

The Ear

Video: How We Hear /Hearing_Loss.html

Outer, Middle and Inner Ear

Outer EarMiddle EarInner Ear Pinna the visible part of the outer ear. It collects sound and directs it into the outer ear canal. External Auditory Meatus (Ear Canal) the tube through which sound travels to the eardrum Tympanic Membrane vibrates when sound waves reach it Malleus (Hammer) tiny bone that passes vibrations from the Tympanic Membrane to the Incus Incus (Anvil) tiny bone that passes vibrations from the Malleus to the Stapes Stapes (Stirrup) tiny bone that passes vibrations from the Incus to the oval window and then to the cochlea Eustacian Tube a tube that connects the middle ear to the back of the nose; it equalizes the pressure between the middle ear and the air outside. Cochlea a spiral-shaped, fluid- filled inner ear structure; it is lined with cilia (tiny hairs) that move when vibrated and cause a nerve impulse to form Semicircular Canals fluid filled tubes attached to the cochlea that help us maintain our sense of balance Auditory Nerve carries electro-chemical signals from the cochlea to the brain Brain processes and interprets signals sent from the ear

Types of Hearing Loss…  There are three types of hearing loss:  Sensorineural  Conductive  Mixed

Sensorineural Hearing Loss  With a Sensorineural loss the inner ear is damaged or not functioning properly  Hearing loss in the presence of a normally functioning outer and middle ear  About 90% of all people with hearing impairments suffer from sensorineural hearing loss

Conductive Hearing Loss  With a Conductive loss the outer or middle ear is damaged or not functioning properly  Hearing loss in the presence of a normally functioning inner ear

Mixed Hearing Loss  A combination of a conductive and sensorineural hearing loss  Both the middle and inner ear are involved

Other Classifications of Hearing Loss  Unilateral  Only one ear is affected  Bilateral  Both ears are affected  Prelingual  Hearing loss occurred before the acquisition of language  Post Lingual  Hearing loss occurred after the acquisition of language. (Usually after the age of two) Unilateral vs. Bilateral Prelingual vs. Postlingual

Degree of Hearing Loss  Hearing loss can be classified by the following degrees:  Mild  Moderate  Severe  Profound

Mild Hearing Loss  A mild hearing loss may cause you to miss 25-40% of the speech signal  Usually this results in problems with clarity  Symptoms:  problems understanding someone farther away than a normal distance for conversation  difficulty understanding even up close if the background environment is noisy  weak voices are also difficult to understand for people with mild hearing losses

Moderate Hearing Loss  A moderate hearing loss may cause you to miss 50-75% of the speech signal  Symptoms:  problems hearing at short distances  difficulty understanding people even face-to-face  difficulty hearing normal conversations  problems hearing consonants in words

Severe Hearing Loss  People with severe hearing loss have difficulty hearing in all situations  Speech may be heard only if the speaker is talking loudly or at close range  A severe hearing loss may sometimes cause you to miss up to 100% of the speech signal  Symptoms:  inability to have conversations except under the most ideal circumstances  most likely cannot understand any speech

Profound Hearing Loss  Profound hearing loss is the most extreme hearing loss  Symptoms  most likely cannot hear any speech at all  inability to distinguish even loud environmental noises  Most likely rely on visual cues instead of hearing as your main method of communication.

Reading an Audiogram Hearing loss is plotted on an audiogram. Right ear is represented by a circle that is sometimes red Left ear is represented by An X that is sometimes blue

Frequency and Loudness  Also called pitch  Measured in Hertz (Hz)  Shown on an audiogram from left to right.  Frequencies are lower on the left and become higher as you move to the right  Measured in Decibels (dB)  Show on an audiogram from left to right  Sound is shown as softer at the top and become louder as you move down Frequency Loudness

Blank Audiogram

The Speech Banana