A PTA test, or pure tone audiometry test, is the standard hearing evaluation used to measure how well you detect sounds at different pitches and volumes. It’s the test most people picture when they think of a hearing check: you sit in a quiet booth, wear headphones, and press a button every time you hear a tone. The whole process takes about 20 to 30 minutes and produces a chart called an audiogram that maps your hearing ability across a range of frequencies.
What Happens During the Test
Before any tones are played, your audiologist will look inside your ears with an otoscope (a small handheld light) to check for earwax buildup or anything that could affect results. If you wear hearing aids, you’ll need to remove them so the test measures your natural hearing.
You’ll then sit in a sound-treated booth designed to block outside noise. The audiologist places headphones or small insert earphones over or in your ears and plays a series of pure tones, one pitch at a time. Your job is simple: press a button, raise your hand, or say “yes” whenever you hear something, even if it’s extremely faint. Testing starts at a mid-range pitch (1,000 Hz) and works upward through higher pitches before looping back to test lower ones. Each ear is tested separately.
To find the quietest sound you can hear at each pitch, the audiologist uses a specific pattern. After you respond to an initial tone, the volume drops by 10 decibels. If you stop hearing it, the volume increases by 5 decibels. This back-and-forth narrows in on your threshold, which is defined as the softest level you can detect at least half the time.
Air Conduction vs. Bone Conduction
Most of the test uses standard headphones, which is called air conduction testing. Sound travels through your ear canal, eardrum, and middle ear bones before reaching the inner ear and auditory nerve. This checks the entire hearing pathway from outer ear to brain.
If results suggest hearing loss, the audiologist will also do bone conduction testing. A small vibrating device is placed on the bone behind your ear. This sends sound vibrations directly to your inner ear, bypassing the ear canal and middle ear entirely. Comparing the two results reveals where the problem is. If bone conduction hearing is normal but air conduction hearing is reduced, the issue is in the outer or middle ear (a conductive loss). If both are equally reduced, the problem is in the inner ear or auditory nerve (a sensorineural loss). Some people have a mix of both.
Reading Your Audiogram
Your results are plotted on a graph called an audiogram. The horizontal axis shows pitch (frequency in hertz), from low sounds on the left to high sounds on the right. The vertical axis shows volume (in decibels), with quiet sounds at the top and loud sounds at the bottom. Each mark on the graph represents the softest sound you could detect at that pitch.
Standardized symbols make it easy to tell your ears apart. A red “O” marks right ear air conduction results, while a blue “X” marks the left ear. Bone conduction results use bracket-shaped symbols like “<” or “[“.
The pattern your marks create tells a story. If they cluster near the top of the chart, your hearing is normal. If they slope downward at higher frequencies, you may have the kind of gradual high-pitched hearing loss common with aging or noise exposure. A flat line further down the chart suggests more uniform loss across all pitches.
What the Decibel Ranges Mean
Hearing ability is classified by the American Speech-Language-Hearing Association into specific ranges based on your thresholds:
- Normal: -10 to 15 dB
- Slight: 16 to 25 dB
- Mild: 26 to 40 dB
- Moderate: 41 to 55 dB
- Moderately severe: 56 to 70 dB
- Severe: 71 to 90 dB
- Profound: 91 dB or greater
In practical terms, mild loss means you might struggle to follow soft speech or conversation in noisy rooms. Moderate loss makes normal-volume conversation difficult without amplification. Severe and profound loss means most speech is inaudible without hearing aids or cochlear implants.
The Pure Tone Average
Your audiologist will also calculate a number called the pure tone average, sometimes abbreviated PTA as well. This is the average of your hearing thresholds at four key frequencies: 500, 1000, 2000, and 3000 Hz. These frequencies matter most for understanding speech, so the pure tone average gives a quick snapshot of how well you hear in conversation. It’s the single number most often used to summarize your overall hearing level in each ear and to track changes over time.
Testing for Children
The same basic test works for kids, with age-appropriate modifications. Children who can’t reliably press a button or raise a hand may be tested using visual reinforcement audiometry, where a toy lights up or moves when they turn toward a sound, or conditioned play audiometry, where they’re taught to drop a block in a bucket each time they hear a tone. For very young children who can’t tolerate headphones, sounds can be played through speakers positioned near the child instead.
Other Meanings of “PTA Test”
In brain injury medicine, PTA stands for post-traumatic amnesia, and a PTA assessment measures how confused or disoriented someone is after a head injury. Scales like the Galveston Orientation and Amnesia Test (scored out of 100) and the Westmead PTA Scale (scored out of 12) ask patients questions about their name, age, location, the date, and recent memories. A score below the cutoff (75 on the GOAT, 11 on the Westmead) indicates the person is still in a state of post-traumatic amnesia. These assessments are repeated daily or more often to track recovery.
In rare contexts, PTA can also refer to plasma thromboplastin antecedent, an older name for clotting Factor XI. A deficiency in this factor causes a mild bleeding disorder sometimes called hemophilia C or Rosenthal syndrome, diagnosed through specialized blood clotting tests. Unless you’re researching a specific bleeding disorder, the hearing test is almost certainly what brought you here.