Enter the threshold levels for 500Hz, 1000Hz, 2000Hz, and 4000Hz, into the calculator to determine the pure tone average.

Pure Tone Average Formula

The following formula is used to calculate a pure tone average.

PTA = SUM(TL) / 4

  • Where PTA is is the pure tone average
  • SUM(TL) is the sum of the threshold levels at the following sound frequencies:
    • 500 Hz
    • 1000 Hz
    • 2000 Hz
    • 4000 Hz

To calculate the pure tone average, add together the threshold levels at all of the hertz levels and divide by the number of levels (i.e 4 like the formula above).

What is a pure tone average?


A pure tone average is a measure of the average hearing sensitivity a person has at various frequencies.

These frequencies are typically measured at 3, 4, or 6 different frequency levels.

How to calculate pure tone average?

Example Problem:

The following example problem outlines how to calculate a pure tone average:

First, determine the sensitivity at each of the 4 frequencies above:

In this example, these are as follows:

  • 500 Hz = 5
  • 1000 Hz = 6
  • 2000 Hz = 7
  • 4000 Hz = 8

Next, add up all the values: 5+6+7+8 = 26

Finally, divide the sum by 4 to get the pure tone average.

PTA = 26 / 4

PTA = 6.5