The record function is a good idea as you can hear what you're saying and compare with the tutors if you don't instantly get a 100% score, but it only works occasionally.
I'm using Chrome (latest version) on Linux Mint and the microphone in my laptop. I really don't think a headset microphone would help at all as occasionally if I try to playback what I said it sounds just like me talking, and there's no background noise, so it's not a hardware problem. I've got a 32M-bit connection as measured by a engineer, and I'm connected via a LAN cable.
For example, today, on module 4.2 on the hear it say it test (second last one) the phrase was "Qu’est-ce qu’on cuisine dans la cuisine ?" and what I recorded sounded like "suptebabaja" spoken very quickly (it took several attempts for me to transcribe that) ; it's as if what I said was sampled at random intervals and most if it thrown away. I just went back to it to check and I had to restart the lesson but now the record only has a few short segments missing, it sounds mostly like it should but as if it's on a mobile phone and breaking up a bit. I started the exercise from the beginning and record started as very clear and seems to have deteriorated as I went through it, but that's just a guess. I'll keep some notes and see if that pattern repeats.
I've been resorting to speaking slowly in a comedy accent to try to get past the AI, but I don't think that's a good way to learn. Right now I'm thinking of recording on my phone as a work round but that's a big nuisance, any chance of a fix?