I am a song composer. I use audacity to record vocals of singers along with my music track. As I start recording, I am not able to hear the vocal of singer in my headphones. I hear the music playing, but not singing sound of singer. Recording the vocals are all fine with no issues. Please help how to listen the sound of singer in headphone while recording. I am using Behringer U-Phoria Studio Recording equipment with my laptop for recording.