Hi AndrisChess,
Please ensure that the sound is turned on
see screenshot   

https://mega.nz/file/Xt0gCCxT#8MO940eHFdRONclvuqBHW2jCUC3WlwMvfuB8VGZPYjA

(In case you're using a mobile device, you'll find the sound settings in the bottom left corner)

If the sound is turned on but you still don't hear anything clear your browser's cache or try using a different browser.

Kind regards,
John