capture sound (and only sound) for flash cards

[oui]

I will use virtual flash cards (for ex. in application "granule" but other are available for ex."parley" in KDE etc.) to learn words of (for me) new languages. granule offers the choice to record the sound of the spoken word or sentence. I can get such sounds.

I can easily get a lot of them from video sequences found in the web.

but how to or with which application capture only the sound part from the videos from standard sound output from PC (from alsa, probably the most easy way) or from pulse audio (seams more difficult as the front ends from pulse audio occupy a lot of place on the screen and it is difficult to operate with them and at the same time with other applications (those where you are looking for the sounds out videos or dialogues where a spoken sound is given)?

[debiman]

ffmpeg, youtube-dl

[Dai_trying]

Also you could use audacity and select your machines output as the recording input.