We will now explain each of these tests in more detail with the use of easy understandable terms
A) TONE TEST
Tone tests provide information about how softly a person can hear tones of different frequencies (pitches). Most sounds are between the frequencies of 125HZ and 8000Hz. Low frequencies are lower numbers and high frequencies the higher numbers. Tone tests have 2 parts, air conduction and bone conduction.
Air conduction tone tests evaluate all parts of the hearing mechanism (the outer, middle and inner ear areas and also the hearing nerve). A person wears a headphone in a soundproof booth and the acoustician then presents the sounds using an instrument called an audiometer. The patient is asked to respond whenever a tone is heard and the tester finds the softest level that a tone is heard at least 50% of the time at each threshold.
Bone-conduction tone tests evaluate only the inner ear and the hearing nerve and are done if the air conduction tests revealed a hearing loss. The patient has a small bone-conduction vibrator placed on the bone directly behind the ear and the sound from the audiometer is sent through the bone vibrator instead of the headphones. The patient is tested for threshold at each of the frequencies again. By testing the whole hearing system (air conduction) and then just part of the system (bone-conduction), acousticians can discover which part of the hearing mechanism is not working properly.
B) SPEECH TEST
Speech tests are done to 'double check' that the pure tone tests results were accurate and also to give even more information about how we hear. A person may be able to HEAR speech (threshold), but not UNDERSTAND speech (discrimination). Speech testing includes both Speech threshold and speech discrimination tests. During these tests, the patient wears headphones just like the test for air conducted tones.
Speech threshold test is done to find out how SOFTLY a person can hear and understand speech. The patient may be tested to find out how softly he can hear speech, how softly they can understand speech, or they may be tested for both hearing and understanding speech. Words are presented through the audiometer at decreasing levels. Again the threshold is determined by the softest that can be correctly identified at least 50% of the time.
Speech discrimination test is done to find out how well a person can discriminate or distinguish words presented at comfortable levels. A list of words are presented and the patient is asked to repeat the words back. The words are at a volume level that the patient finds both comfortable and loud enough to provide the best possible results. The list of words that are used reflect the sounds of the language of the patient. Speech testing may be done via recorded voices (male or female), or via monitored live voice. In this case the individual giving the test watches a meter to make sure that their voice is being presented at the proper intensity.
C) COMPLIANCE TEST / IMMITANCE TEST
The purpose of this test
is to evaluate how well the middle ear is working. The tester will place a small probe into the patient's ear
that will seal the air in the canal. A small pump will then take some air out of the canal and then put extra
air back into the canal to see how well the eardrum moves in and out. There is usually no
pain at all, just
a slight feeling of pressure in the ear.