1. Set a comfortable level
Use the same headphones, quiet room, and device volume for every measurement in a session. Start low and play a practice pair. Keep the masker comfortably audible. Never raise device volume just to hear a difficult probe.
2. Listen to two intervals
Each interval lasts 600 ms, with a 350 ms gap. One contains a 300 ms pure tone in its middle. Its interval is randomized. Choose interval 1 or 2, even when unsure. Baseline trials compare the tone against silence. Starting a test plays the first pair automatically. After you choose an interval, the next pair plays automatically within the current frequency test. When that test ends, the next untested frequency is selected; press Start threshold test to begin it. You can also choose a frequency from the checklist between tests. Stop audio pauses the test; Resume test continues it. The practice pair always places the tone in interval 1 and is not recorded. Play probe only previews the selected tone without a masker and does not record a response; it is available before a test or while paused.
3. Follow the adaptive test
Two correct answers lower the probe level; one incorrect answer raises it. This staircase targets approximately 70.7% correct. Steps start at 4 dB and shrink to 2 dB after two reversals. The test ends after eight reversals; the threshold is the average of the last six reversal levels. Method: Levitt (1971).