Hearddle

Play the tones, then tap the one that's off-pitch. 10 rounds, getting harder.

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About Hearddle — spotting the off-pitch tone

Hearddle trains odd-one-out pitch detection — picking the single tone that sits slightly off from its neighbours. Catching a note that is a touch sharp or flat is exactly what a choir singer does when one voice strays, or what you do when an instrument slips out of tune partway through a piece.

Ten rounds each play a small group of tones with one off-pitch member. Tap the odd one out. The gap shrinks as you go, so every round asks a little more of your ear.

How small a difference can anyone actually hear? Our guide to the just-noticeable difference explains the limits of pitch resolution and how practice moves them. See all our ear-training guides to dig deeper.