How to turn up the volume on a nikon d90? I want to make a movie?

How do you turn up the volume on a nikon d90? I want to make a movie?

It is not in your user manual?

Most non-video cameras with a video feature use auto audio attenuation.

Before you start making a movie (video), practice with the camera and get used to using it.

Do you have a script already?

The D90 does not have the ability to raise and lower the volume of the microphone on it. Also the microphone on the D90 only records single channel audio which if you are making a movie you usually want stereo. If you do decide to use the D90 you should be able to raise the volume in post-production with video editing software such as Avid, Premier, iMovie or Final Cut