Hearing Health Guide
Definition
An audiogram is a standardized graph generated during audiometric testing that records a person's hearing thresholds across a range of frequencies. The horizontal axis shows frequency (pitch) in hertz (Hz), from 250 Hz on the left to 8,000 Hz on the right. The vertical axis shows intensity (volume) in decibels hearing level (dB HL), with quieter sounds near the top. Each point plotted represents the softest sound detectable at that frequency per ear.
Frequency (horizontal axis): The left side of the audiogram shows low-pitched sounds (bass voices, rumbling) beginning around 250 Hz. The right side shows high-pitched sounds (birds, doorbells, sibilant consonants like S, F, TH) up to 8,000 Hz. Most of what makes speech intelligible falls in the middle range, from about 500 to 4,000 Hz.
Volume (vertical axis): The top of the vertical axis represents very quiet sounds (0-10 dB HL). Moving downward represents louder thresholds, meaning more hearing loss is needed to detect those sounds. A point plotted at 60 dB means that frequency must be played at 60 dB before you can hear it, a moderately loud level.
The standard convention uses 'O' (circle, red) for the right ear and 'X' (cross, blue) for the left ear, per AAA/ASHA standards. Each ear is tested separately. If both ears have the same results, the symbols overlap. Brackets and arrows indicate bone conduction measurements.
The 'speech banana' (a banana-shaped region on the audiogram spanning roughly 500-4,000 Hz at 20-60 dB) is where most speech sounds fall. Thresholds within this region indicate the ability to hear conversational speech; thresholds below it indicate speech is being missed.
Normal: 0-25 dB HL. Mild: 26-40 dB. Moderate: 41-55 dB. Moderately severe: 56-70 dB. Severe: 71-90 dB. Profound: 91+ dB. These categories are defined by the American Academy of Audiology and applied per ear, per frequency range.
The pattern of loss across frequencies matters as much as the degree. A 'ski-slope' pattern (normal lows, elevated highs) is typical of noise-induced or age-related loss. A 'flat' pattern (equal loss across frequencies) may indicate other causes. A 'notch' at 4,000 Hz is a classic indicator of noise damage.
Common Questions