Earboard is an ear trainer for musicians whose purpose is to generate note intervals to play along with. Its layout is modeled on the fretboards and standard tuning of stringed instruments like guitar and bass.
Click SELECT NOTES to exclude notes from the random pool.
NEW plays a new interval.
Toggle the display of the interval with SHOW.
DIRECTION controls in what order to play the two notes of the interval.

KEYBOARD SHORTCUTS
ARROWS - move selection
SPACEBAR - play selected note
N - new interval
R - repeat interval
A - switch autoplay
S - toggle show
C - toggle chord

Source code