The basic hearing test or audiogram tests one's ability to hear pure tones in each ear. Best results are obtained by a trained audiologist in a special soundproof testing booth. Simple tests, such as ones done in many schools, may be useful for screening, but a careful audiogram is necessary for accurate diagnosis of most hearing problems. A comparison between these two type of conduction can be very useful in localizing which part of the hearing mechanism is responsible for the loss. The results of audiograms are most often displayed in graph form.
High frequencies correspond to high tones, and low frequencies are low tones.
Most audiograms go from around 250 hertz to 4000 hertz. Hearing losses over 20 decibels are considered abnormal. In the audiogram to the left, the red tracings are for the right ear, and the black tracings are for the left. The round circles represent the air conduction and the brackets are the bone conduction. Low frequencies are to the left and high frequencies are on the right.