A common question is "What type of permissions the browser will ask for?". When you install and configure your voice widget, your visitors will be asked to allow speech recognition. It depends if you use HTTPS or HTTP version, this behavior can be slightly different, but in general HTTPS version will make sure that their choice is saved for the next sessions.
Browsers' speech recognition behaves differently based on the protocol used:
For excellent user experience, don't compromise on anything less than HTTPS (available free with Let's Encrypt).