I've just left them. There's nothing wrong with them and I passed their tests but after about 6 months I just didn't get any work at all, unlike Utest where I'm pretty busy most of the time and get bits of work from Testbirds (which I joined at the same time as Testlio). Maybe your skills may match them better, so it's worth at least signing up probably.
I've not worked for them but the other crowdtesters I work for don't require a mic generally. I have had a couple of voice recognition ones in the past and running commentaries on UX but it doesn't happen often. I wouldn't worry about it yet.