I'm sure they're doing their best to provide us with good results. I know that sometimes the audio is a bit hard to understand, but it's not that easy to give us new audios from time to time. They've done their duties already, now it's our problem how to deal and solve those audios. There are a lot of things that can help us to understand those audio captchas. For example you can download equalizers and audio boost or you can just simply use earphones/headphones too