I have tested it, it worked。
It should be safe, it is based on Flash Player with micro phone support you may need to change “settings” of flash player to let micro phone work.
You can mute human voice by switch the sound track in play control (通过在播放控制中的切换声道按钮，可以消去原唱)
效果还可以，当然不能和KTV 包房比，不过这里太贵。 聊胜于无
Happy New Year 2011