I can't hear the sound.

Hello. I bought ddj wego 2 today. But I cannot hear the sound although I downloaded virtual dj LE and ddj wego 2 ASIO driver 1.000 through internet (My laptop does not have CD ROM so I got the settings from online). I updated firmware and I still can't hear the sound. BTW, I only use headphone to hear cuz I don't have a equipment for MASTER OUT. Does it matter on my problem? Why can't I hear the sound