A source of sound, like a drum sends out vibrations, or sound waves, which stimulate the auditory nerve in the ear, These sound waves are measured in two ways.
1. FrequencyA hearing test plots your response to a number of sounds, varying in frequency and intensity. The machine used is called an audiometer, and the graph that is plotted is called an audiogram. The line that is plotted on the audiogram tells you how loud sounds have to be for you to hear them. The sounds on the left hand side of the audiogram are the low pitched sounds, and the sounds on the right are the high pitched ones. The lower your line is on the audiogram, the louder the sound needs to be before you can hear it.The pitch, how high or low the sound is. This is measured in the number of cycles that occur in one second. The closer the waves are together, the more cycles per second there are. and hence the higher the pitch. The unit used for measuring frequency is Hertz (Hz).2. IntensityThe loudness of sound. This is measured in decibels (dB). The more decibels, the louder the sound.
For a detailed explanation of an
audiogram visit "Understanding
your Audiogram"
Always remember
"The audiogram provides no information
on the quality of audition present at these levels. It merely indicates
the dividing line between hearing and not hearing, much as a shoreline
divides land from water. From looking at the shoreline it is impossible
to deduce the water's depth, warmth, or its suitability for drinking or
swimming. ……..It is possible for several children with identical pure-tone
audiograms to differ greatly in ability to use residual hearing and to
discriminate speech."
(taken from Ling, D (1976) Speech
and the hearing impaired child: theory and practice. Washington, DC: A
G Bell Assoc. for the Deaf, p 23-25)