It happens many times that we wish to listen to the audio only from the videos that we possess and for that we need to extract or rip the audio from the video files. We have mentioned the process to that thing earlier but here is an interesting way with which you can take out the audio directly from the Youtube videos even without downloading the video.
For extracting audio from Youtube videos:
There are many tools available to download video from Youtube but FLV Extract is a great tool that provides you with an option to either download video or audio or both from the Youtube videos. What you have to do is just drop the flv files on the software.
For downloading only Audio directly from Youtube:
Youtube videos are either in the .Flv (low quality) or in the .Mp4 (high quality) format, but if you wish to download only the audio and not the video then you can do that easily.
Listentoyoutube is a great site that converts flv to mp3 and provide you with the download link so that you can only download the audio directly.
For the rest of the video formats:
Read this earlier post that will let you know how to extract audio from video files.