Ed said, "If you bother to learn how to use them, ears are quite good."

Ed, that depends on the ears. They come in quite a variety. Some work excellently and some not worth a sh**.

I am old enough to remember before electronic tuners and I used to get my guitar in tune and then tune the Autoharp to the guitar. The 'harp had almost the same range as the guitar. Its lowest note was the first fret of the low E string and its highest was the C at the last fret of the first string. Nowadays folks modify their 'harps so much that almost every one is different.