2 Alternative Forced Choice (AFC) 3-down 1-up
(with individual termination of the experiment)
You will hear two very similar sounds.
Pay attention to see if you hear a difference.
Are you ready?
2 Alternative Forced Choice (AFC) 3-down 1-up
Stimuli and procedure
A pair of tones is played. 3 pairs with a similar frequency gap are played per 'level'. When in all 3 presentations per 'level' the higher tone is identified correctly, the frequency gap between the tones is reduced for the next 'higher level'.
If an incorrect answer is given, the first item of the next 'lower level' is used for the next presentation.
Test termination
The test is finished individually, after the user does have the impression to have reached the threshold, namely 'level N' which could be identified correctly and consistently.
Result
The frequency gap at 'level N' is considered the result.