If you suspect you have hearing loss you need to visit your family doctor. They can check for signs of a medical condition that would affect your hearing. Of the two types of hearing loss, conductive and sensorineural, it is sensorineural hearing loss that is generally corrected with a hearing aid. Your doctor will examine your ear with an instrument called an otoscope. With an otoscope, your doctor can see if there are any abnormalities in your ear canal or eardrum. The next step is to conduct a full hearing test. One portion of this test is the pure tone testing, which measures how well you hear different frequencies. You will be asked to listen to a series of tones at various volumes, and to indicate when you hear them. Each ear will be tested separately. Another type of pure tone tests involves the placement of a small bone conductor behind your ear, which allows sound waves to be transmitted directly to the cochlea of the inner ear, bypassing the middle and outer ear.
After the pure tone tests, you most likely will have to take a series of speech tests. Here you will be asked to detect and understand speech. You will hear a series of words that you will be asked to repeat. The words will vary in intensity and length. An impedance test is used to measure the transmission of sound through the middle ear. An audiologist will check this by placing a probe in your ear and measuring the transmission of various tones and frequencies at different air pressures.
The results of a hearing test are usually presented in a chart known as an audiogram. Your audiologist will explain this chart to you. It will show your perception of different frequencies, and compares that with the expected values. An audiogram is a useful tool in measuring the progress of hearing loss over time. An audiogram will present the results in terms of decibels. A decibel is a logarithmic measure of sound intensity. Zero decibels is defined as the intensity that a normal person can hear fifty percent of the time. A normal conversation occurs at about forty five decibels, and one hundred and twenty decibels is the noise a 747 would make while taking off.