Nobody can tell you anything without proper system info or other technical details. Just saying that it doesn't work is not good enough. You need to provide system info, version of AE, audio settings, what files you are working with and so on.
OS - Windows 10 64bit (10.0, Build 10586)
Adobe - After effects Cs6(2012)
Graphics card - NVIDIA Quadro NVS 160M
current display mode- 1440x900(32bit)(60hz)
Sound - Speakers/Headphones(IDT high definition Audio
i just inserted a audio file into it and pressed play and no sound is present