AudioExpert: Online Sound Editor & Converter

Audio Expert is a free online sound editor that helps you to edit audio, convert it from one file format to other, merge different tracks and record sounds. Using this tool, you could quickly crop audio files, merge multiple files, batch convert multiple audio files, record your voice through a microphone and then download the resulting file.

http://www.makeuseof.com/dir/audioexpert-online-sound-editor