I'm currently trying to expand my ear, so I'm transcribing this disc by ear, "Carol Kaye's Hit Bass Lines". It's got all the bass lines from a bunch of songs recorded solo. It's awesome! Challenging stuff (for me, anyway), and no straining to pick out the bass lines. It's hard, but I'm hoping to get through the whole disc eventually. If you're looking to build your ear, I think this might be worth your time to look into. I'm digging it! Here's a link,
The Official Carol Kaye Web Site