office telephone Rj9 cable to mobile headphones

the problem is there are 2 grounds in the rj9 _{so if I connect them with the headphones i hear that whistle}

@Møhámèd Âbđállàh - Why are you connecting both together the current level is not high enough to require it.

then how should I get the mic working together with the sound ? the headphones have only one ground .

@Møhámèd Âbđállàh - Most headsets have one common ground at the plug end. You have Left +, Right + and Mic + and then the shared ground.

Did you review the URL link I posted to @jayeff great answer?

@danj

sorry for late response ..

I have reviewed jayeff's answer ,

I have 4 wires at the end of the headphones

blue : right audio

green : left audio

yellow : ground

red : mic

and at the rj9 cable there are 4 cables ..

assumingly : the first and the last one are for the mic and its ground and the 2 middle wires are for mono audio with its ground ,,,

I tried to make the connection like that :

1. green and blue : mono audio+

2. red : mic+

3. yellow : audio- and mic-

when I connect the mono audio with green and blue _{and the mono audio ground to the yellow} the audio works perfectly ,,

and when I try to connect the mic to red and its ground to the yellow ( so there are two ground connected with the yellow wire) , I hear a terrible whistle within the headphones themselves .. so I don't know what am I doing wrong ..

I hope you can help me ..