By Dr. Allan S. Mehr, FAAA
| An
audiogram is a picture of your hearing. The results of your
hearing test are recorded on an audiogram. The audiogram
to the right demonstrates different sounds and where they
would be represented on an audiogram. The yellow, banana-shaped
figure represents all the sounds that make up the human
voice when speaking at normal conversational levels. |
|
| The
vertical lines on an audiogram represent pitch or frequency.
The 125 Hertz (Hz) vertical line on the left side of the
audiogram represents a very low pitch sound and each vertical
line to the right represents a higher pitch sound. Moving
from left to right on the audiogram would be consistent
with moving from left to right on a piano keyboard. The
most important pitches for speech are 500-3000 Hz. |
|
| The
horizontal lines represent loudness or intensity. The 0
decibel (dB) line near the top of the audiogram represents
an extremely soft sound. Each horizontal line below represents
a louder sound. Moving from the top to the bottom would
be consistent with hitting the piano key harder or turning
up the volume control on your stereo. |
|
| Therefore,
every point on an audiogram represents a different sound.
For example, point A on the audiogram to the right represents
a soft low-pitch sound and point B represents a soft high-pitch
sound. Point C represents a loud mid-pitch sound. |
|
| The
softest sound you are able to hear at each pitch is recorded
on the audiogram. The softest sound you are able to hear
is called your threshold. Thresholds of 0-25 dB are considered
normal (for adults). The audiogram on the right demonstrates
the different degrees of hearing loss. |
|
| The
audiogram on the right represents the hearing of an individual
with normal hearing in the low frequencies (pitch) sloping
to a severe high frequency hearing loss in the left ear
and a moderate to severe hearing loss in the right ear.
The blue Xs indicate the thresholds for the left ear and
the red Os indicate the thresholds for the right ear. |
|
| If
we now superimpose the normal speech area on the audiogram,
we can obtain some information regarding this individual's
ability to hear speech. The listener is able to hear all
the low and mid speech sounds but is not able to hear the
high pitch speech sounds (ie. F, S, TH) in the left ear
(blue X's). The listener is not able to hear any of the
normal speech sounds in the right ear. This person would
rely on the left ear for speech understanding and would
probably experience difficulty hearing in noisy environments. |
|