. Welcome to 7S. Glad to have you man. It seems as though you're misnaming everything. I would not consider this a "simple login" but a key validation. As I assume you're learning as you go...here's a few tips.
Do not store any license keys client side. I can not stress this enough. If you're going to have an actual product you need to validate it via web or some other form.
If you're going to do it client side...at least encrypt it in some way. I mean...sure it's still susceptible to brute force or being reversed (depending on how you do it) but at least it's better than plain text
Get a mic, even a crappy $20 mic will do. You don't have to have some fancy $200 mic.