Left speaker and mic is not working?

I have this headphone link below.

son-tech.de/Salar-V80-Professional-Earphones.html

Proble is left speaker and mic is not working. i used it a month ago last time. when everything was working ok. but after a month i plug in so i find that problem.

When i plug mic jack in computer it. produce noise but when i speak into it. nothing happen it continue producing noise. but not my voice. can you help?