help please its audio problem but big problem!

i have speakers logitec 5.1 and asus by Realtek program, the problem is: on games for example witcher, call of duty (story).. then the some characters or the main speaker talk i cant hear them butt i can here the same time then he speak the backround voices like the rain or the cars on the same time which i watche the subtitles of his speaking, i have try so mush to do somethink but nothing can someone help me? if i recorder the time which i cant hear the main voice then in the video looking normal, i can hear everything, and i say again i cant hear some on that voices i remeber a moment with 3 characters on call of duty i cound hear the others characters and i couldnt here my characthers but when i was talking i could here the backround help guys! or on witcher i cant never hear the characters then they talk but i can hear the same time the backround