To unblock your microphone, do the following:
Click on the microphone symbol in the address bar of your browser.
The following Infobox appears:
Here you will find the option to allow microphone access. Click on “Always allow https://recorder.calipio.com to access your camera”.
Reload the page by pressing the “F5” key on the keyboard. Alternatively, you can press the “Reload page” button next to the address bar.