10 Trainers for eye and ear
If you search for music theory sites on the internet, you’ll find several that provide interactive drills, often called trainers. These aim to help you improve particular skills that are involved when using staff notation. They are useful for coordinating your eye and your ear, that is, coordinating looking at notation while listening to sounds. Admittedly you need regular practice to make headway with the drills. However, with steady application (and a degree of patience) you will find that, through using these drills, your eye and ear will become much more proficient at identifying different aspects of the music you are looking at and listening to.
Indeed, many aspects of staff notation lend themselves to drills. It is a relatively straightforward process to create drills for note-naming, identifying rhythms, scales, key signatures, intervals, chords and so on. In addition, drills for improving a particular skill can vary in scope. With note-naming, for instance, a drill might ask you to identify notes on the treble staff, or on the bass staff, or both; it might also include notes with ledger lines. A drill for a particular skill can also have different levels of difficulty from which you can choose.