Audio not loud enough???

Hi. I am fairly new to the whole DVD ripping process but i am now successfully burning dvd's on to disc using Nero Startsmart Essentuals. The only problem that i am having is that the audio is too low and it's sometimes hard to follow conversations. Is there something i can do in the settings of Nero to alter the sound quality or is there something else that i can possibly do to improve the sound quality? Thanks in advance, Aussiez.