7 Replies Latest reply: Jul 18, 2013 10:49 AM by SteveG(AudioMasters) RSS

    Need Very Advanced Noise Reduction Help

    VinnieBoomBaats

      Greetings all, This will probably be an odd request if not a first for the forum. I am one of those (some say bizarre)  people that does ghosthunting and I have used Audition for reducing the noise in my recordings for some time. Recently I have been expirimenting with new recording methods that work very well regarding what it captures, but that are also very challenging to enhance and clean up. I just cannot seem to find the right combination, I can make the areas of interest sound fair, but I suspect there is a way to make them even better, I just cannot seem to get there......thus I am hoping that I can get some 1 on 1 help from a master.

       

      I am on mac ver cc btw.....I can guarantee that the right person will find this quite interesting...thanks in advance to anyone willing to assist me...

        • 1. Re: Need Very Advanced Noise Reduction Help
          Bob Howes MVP

          Have you tried the usual trick of doing several light passes instead of trying to get all the noise at once?  That usually gives the best results (though at the expense of time taken).

           

          Grab a noise sample they run the noise reduction with is set to very light reduction.

           

          Once this is done, increase the FFT sample size and grab another noise sample--then run NR again at a lowish setting.

           

          Repeat until you're happy with the results--3 or 4 passes will normally do it.

           

          Working this way seems to let you get to a good level of noise reduction but without the artifacts you'll find if you try to do everything in one pass.

           

          Give it a try and let us know if you find any ghosts!

          • 2. Re: Need Very Advanced Noise Reduction Help
            SteveG(AudioMasters) Community Member

            Unless you have a lot of low frequency noise, then the most effective NR will be done at high FFT settings. This inherently reduces the artefact level, and that's something you probably should go for anyway, because these could easily be mistaken for ghost noises...

            • 3. Re: Need Very Advanced Noise Reduction Help
              Bob Howes MVP

              Or leave the FFT setting low and claim you've found the ghost of Cool Edit 96!

               

              Seriously, I've generally had good results creeping the FFT setting up for subsequent passes but, for ghost noises your suggestion makes sense.

              • 4. Re: Need Very Advanced Noise Reduction Help
                SteveG(AudioMasters) Community Member

                We should probably stop taking the rise here... Whereas as a scientist, I've not seen a shred of credible evidence for ghosts, I haven't seen any absolute proof that they can't exist, either.

                 

                The major problem with using NR under these circumstance is that certainly, you can remove uncorrelated 'noise' from a recording - but if you do, you have altered the relative levels of what's left to the previous background, so you've lost perspective. And anybody running a seismograph will be able to demonstrate that there's quite a bit of noise and microscopic movement in the ground anyway. And that stuff makes buildings move slightly too - which can create noises you didn't expect.

                • 5. Re: Need Very Advanced Noise Reduction Help
                  VinnieBoomBaats Community Member

                  To all that have commented thus far, thank you, I continue to read through help files and try methods I see in other posts. I can appreciate anyones suspicions but I dont refer to simple noises here, I refer to actual verbal responses to questions in the recordings. I have been doing this for many years and my standards for what I consider to be something valid are quite high. I have to be able to actually hear something in the raw recording at normal levels before i decide to try and work on it. I dont try to find things and think burbles and other artifacts are valid, I have to be able to hear words.

                   

                  Would anyone be willing for me to send them a clip to work with and see what they can do?....I am still perfecting my new expirimental method but I could have something fresh in a couple days?

                  • 6. Re: Need Very Advanced Noise Reduction Help
                    Bob Howes MVP

                    I'm probably one step along from SteveG.  While not convinced of the existence of ghosts, I have on a couple of occasions seen things I couldn't explain with any logic.

                     

                    Anyway, with no promises, I'm happy to have a go at a sample of your recording--I think I have a few quiet days until Monday when I'm back to dealing with doctors down in Brisbane--so, either what you have now or something new from Tuesday onwards.  If you want to post the best quality copy you can manage somewhere and PM me the details, I'll have a play.

                    • 7. Re: Need Very Advanced Noise Reduction Help
                      SteveG(AudioMasters) Community Member

                      Bob Howes wrote:

                       

                      I'm probably one step along from SteveG.  While not convinced of the existence of ghosts, I have on a couple of occasions seen things I couldn't explain with any logic.

                      Oh, I've seen loads of things that logic fails to explain. In fact, one of the things that intelligent people waste most time on is trying to figure out the 'logic' behind the less intelligent actions/comments of others...