Hearfork
Play the tones, spot the off-pitch one, then judge how much lower or higher it is. 5 rounds, getting subtler.
About Hearfork — measuring your pitch threshold
Hearfork measures the fine end of your pitch sense — your just-noticeable difference, the smallest pitch gap you can reliably hear, reported in cents. A sharper threshold means surer intonation: it is what separates a tuning that is "close enough" from one that is truly locked in, for singers and players alike.
Each round plays three tones with one off-pitch. Spot it, then judge how much lower or higher it was. Five rounds get subtler, and your smallest correct call sets your threshold for the day.
How small a difference is small? Our guide to the just-noticeable difference explains what the number means and how training lowers it. Pair it with the rest of our ear-training guides.