I just discovered an alternative to the "bass trainer" and "phrase trainers" that are out there...and the price is really right.
If you have a computer, check this program out:
Express Scribe, v.4.22.
http://www.nch.com.au/scribe/index.html
The software is FREE!
This is actually transcription software. It's designed to allow a typist to listen to a spoke-word audio file, while typing. This is the kind of software that secretaries use to type up the boss's dictation.
What's cool about this is that it actually has many features that a musician would love.
It'll play almost any kind of file, including most MP3, WAV, CD audio and WMA music files.
It will allow you to slow down to 25% of the original speed without changing pitch. (It will also allow you speed the file up to 225%).
It even has filters to take out low end sound from the recording.
One of the coolest things, though, is that it will allow you to start, stop, rewind and fast forward the recording using foot pedals--so you don't need to take your hands off the bass.
That's something even the little Tascam and Korg competitors can't do.
You can buy commercial pedals for $70 all over the internet, but the website will also tell you how to make them. I made a three-button pedal from Radio Shack parts for under under $12.
Although this was never intended for musicians, this is the the coolest little software package for a student of the bass that I have evern seen--and it's free!