A Problem about microphone on my computer.

I got a problem about my microphone(default) on my computer.

If I don't turn the Microphone Array and Microphone Boost to zero, the microphone will be howling(some huge sound appear on my computer). This is my setting on micorphone right now:

That's the sound device:

I'm using this computer:

Product name: HP Pavilion dv7 Notebook PC(dv7-6c95dx).

Windows7 System

Some of my friends told me to turn off "listen to this device", but I need this choice. So please help me to fix this problem.

Thanks

PS: My English is not good, please excuse it. If you need any information about my computer or system, I can give them to you. I'm sorry the The microphone enhancements is Chinese.