Transcript severe hearing loss

BASIC OVERVIEW OF THE EAR
AND HEARING LOSS
The Ear
Video: How We Hear
http://hcd2.bupa.co.uk/fact_sheets/Mosby_factsheets
/Hearing_Loss.html
Outer, Middle and Inner Ear
Outer Ear
Middle Ear
Inner 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, fluidfilled 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 vs. Bilateral

Unilateral
 Only
one ear is
affected

Bilateral
 Both
ears are
affected
Prelingual vs. Postlingual

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)
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
Frequency
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
Blank Audiogram
The Speech Banana