I cannot hear my composing sound,

I am a beginner of the Cubase,
At the first time I can hear the sound if I put the keyboard when I tried composing,
But after that day, I tried one a time ‘create empty’ on the 'Dance Music ’ of the production on the begining page.
I closed the project and then I made new project basically ‘instrument just 1track’ but I cannot hear the sound which I put keyboard.
how can I solve it…TT
help me…!

Are you keyboard connected as midi or audio? If audio make sure you have the monitor button enabled (That yellow one next to the record button) on the audio track. Also make sure the input channel is routed to the audio track.