How to turn off the clicking sound of the BT adapter for typing covers?

[rikisyo]

The BT adapter for typing covers has its own speaker which is not affected by the Windows setting on typing sound. The main reason I bought this adapter is to have a silent keyboard. How can I turn off the sound??

Thanks!

 

[rikisyo]

UPDATE: Never mind. I have returned it.

Better investing my $60 on a good BT keyboard instead of this thing.