Plz tell how to clear distortion in a recorded audio?

I have a ';.DAT'; Video recording of a ceremony but the audio in the file is distorted and low . Is there any method to clear the distortion in audio. the ceremony file is very important to me. plz tell if anyPlz tell how to clear distortion in a recorded audio?
There are a lot of audio programs out there such as Audacity, but one way or another it will involve a process of re-encoding the entire video or extracting, editing and re-muxing the adjusted audio. Your best bet, in my experience, all told, is probably to use a program like Sony Vegas or a similar Non-Linear Video editor. You would then render the video with the adjusted audio. What you want to do is amplify and dynamically compress the audio or use a noise reduction algorithm, both can provide very different results and I can not say which is best for your video. This is not an easy to understand process for people who are not very experienced in audio and video editing. The concept of it is that you are ';turning down the volume'; below a certain level of volume (the noise) and ';increasing the volume'; above a certain level of volume (The sounds you want to be heard). It ALWAYS takes a bit of messing around with the settings to get it the way you want it.





Also note that you can't just change it and click save. You will need to rerender, or extract the audio perform the same adjustments to your audio and remux it with the video. That is typically more difficult to do as its' not as common a method. I'm pretty sure TMPGENC (Tsunami MPEG Encoder) can do this.





Also one unknown of sorts is the video itself. .dat is not really standard for video is it from / compressed for a VCD? I would hazard to guess that it is MPG from a VCD, however, if it is not you may find it harder to use the muxing process I described above, and may find you are best off using the edit and re-render method.





Note also that the re-render method you will need to select a video output format as the video is being recompressed/rendered. This may, depending on the settings you are using, cause a degradation in quality of the video and even the audio to a certain degree. I know some programs like virtualdub can essentially re-encode audio without re-encoding video. It is essentially a remuxing process, but I do not have the knowledge to describe how to do this with Virtualdub.Plz tell how to clear distortion in a recorded audio?
some audio soft waress have filter and have ability to raises soud volume,check xilisoft website for the proper software.