Help: how to improve oral english

I have been served in quality management field about 8 years,to be specific, i do SQE,NPI,QE supervior. no wander that i am famliar with the QMS, including ISO9000,TL9000,TS16949 as well as the related manual and tools, for example, APQP,PPAP,FMEA,SPC,MSA,DOE,MINITAB etc. by the way , i am also familar with process of stamping,welding ,plating ,PVD, Oxidization ,cable assembly,injection as well.

The best thing i want to is to find a senior QE in foreign firm with salary during 6k-10k. though i have tried to improve my oral english per attending oral course, recide the new concept english , try my best to use englsih as far as i can ,such as take note,watch ENGLISH program,imiating voa special english . That is true. i can do a basic communication with foreigner . but i know it shall be far more than enough at all.especially, if the firm need u to communicate with foreiger ,direct boss, it is still a big nut to me.

speaking maybe not a big problem, the fetal is hearing .most of time, i can't understand what they are speaking .

do u have any chance to have good approach to help me?