Sony CD-PX240 4GB Digital Voice Recorder

Built-in USB connection. It records in both linear PCM and MP3 formats and is suitable for capturing lectures, meetings, notes, and even live music. It requires no cable to communicate with your computer; simply plug the unit into an available USB port on your computer to move files back and forth. 

Sony voice recorder comes with built-in memory, it also has a space for external memory.

If you're learning how to sing, this is a useful device for you.