18 Replies Latest reply on Sep 5, 2008 9:20 AM by MAMBO_MAN

    Audio--Humming--How to remove

    MAMBO_MAN Level 1
      Hi:
      I Have Adobe Premier Elements 4.0 (APE4), WINXP-SP-2,
      CPU = 2.40GHz, RAM = 1 GIG; 2 HD'S: 20 GIGS & 200 GIGS;
      Windows Media Player 11.

      I HAVE USED PINNACLE'S INSTANT DVD RECORDER TO TRANSFER
      SEGMENTS OF DIFFERENT VHS TAPES TO DVD'S WITH RESULTING
      .VOB FILES WHICH I HAVE THEN (IF NECESSARY) CONCATENATED
      TO A SINGLE .VOB FILE. THIS FILE WAS THEN EASILY LOADED
      INTO APE4 FOR EDITING (ADOBE STATED, AS THE FILE WAS BEING
      LOADED, THAT FIRST IT WAS 'INDEXING' & THEN IT WAS 'CON-
      FORMING' THE FILE--WHAT DOES THAT MEAN??)

      MY PROBLEM NOW IS THAT 2 .VOB FILES SO LOADED INTO APE4
      HAVE A CONTINUOUS AUDIO HUM & FAIRLY LOW VOLUME--THESE
      FILES ARE PARTS OF CONCERTS I TAPED ABOUT 10-15 YEARS AGO).

      IN THE DUMMIES SERIES BOOK ('ADOBE PREMIER ELEMENTS FOR
      DUMMIES,' BY KEITH UNDERDAHL, 2005), IT STATES:
      "DeNOISER: REMOVES UNWANTED BACKGROUND NOISE DURING
      QUIET PARTS OF THE CLIP. THIS EFFECT WORKS KIND OF LIKE
      THE DOLBY NOISE REDUCTION FOUND ON AUDIO CASSETTE TAPE
      PLAYERS BY REMOVING POPS & HISSES FROM THE AUDIO."

      NOTCH: REMOVES SOUND AT A FREQUENCY YOU SPECIFY. USE THE
      EFFECT IF THE AUDIO CLIP HAS A CONSTANT HUM CAUSED BY A
      NEARBY POWER LINE OR A FLOW IN THE RECORDING DEVICE."
      (I DO NOT KNOW THE REASON FOR THE'HUMMING')

      LATER ON, IN THE "TEN ADVANCED TECHNIQUES," HE AGAIN
      MENTIONS "REMOVING AUDIO HUMS" & STATES:
      "..A TOOL THAT MAY HELP YOU REMOVE THAT HUM. THAT TOOL IS
      THE NOTCH EFFECT, WHICH CAN BE FOUND IN THE AUDIO EFFECTS
      FOLDER IN THE EFFECTS WINDOW. THE NOTCH EFFECT REMOVES ALL
      AUDIO AT OR NEAR A GIVEN FREQUENCY WITHIN A CLIP.
      HERE'S HOW TO USE IT:

      1) CLICK & DRAG THE NOTCH EFFECT TO THE THE HUMMING CLIP,
      AND THEN CHOOSE EFFECT CONTROLS TO OPEN THE EFFECTS
      CONTROL WINDOW.

      2) ADJUST THE CENTER SLIDER UNTIL YOU FIND THE FREQUENCY
      THAT IS CAUSING THE HUM.

      IF THE HUM COMES FROM A POORLY SHIELDED POWER CORD, ADJUST
      THE CENTER SLIDER TO 60 Hz IF YOU LIVE IN AN AREA THAT
      USES NTSC VIDEO
      (DOWN FROM THE DEFAULT SETTING OF 1,495.0 Hz--SEE BELOW??)

      3) ADJUST THE Q SLIDER TO BROADEN THE FREQUENCY RANGE OF
      THE SOUND THAT IS REMOVED.
      BE CAREFUL NOT TO BRAODEN THE RANGE TOO MUCH OR THE AUDIO
      QUALITY WILL DIMINISH CONSIDERABLY."

      NOW IN THE PREMIER ELEMENTS 4 SOFTWARE--THE RIGHT SIDE OF
      THE INTERFACE IN THE EDIT PANEL--HAS A SECTION CALLED 'FX
      EFFECTS.'
      CLICKING ON THAT OPENS UP A PANEL CHOICE OF EFFECTS
      (VIDEO, ETC.)
      SELECTION THE AUDIO EFFECTS OPENS UP MULTIPLE AUDIO EFFECTS.

      QUESTION:
      DO YOU DRAG THE "NOTCH" ICON TO THE CLIP IN THE SCENELINE OR
      TIMELINE, AND DO YOU DRAG IT TO THE AUDIO PART OR THE VIDEO
      PART OR DOES IT MAKE NO DIFFERENCE??

      THERE IS A SECTION ENTITLED "EDIT EFFECTS"
      CLICKING ON THAT GETS CHOICES--INCLUDING:
      VOLUME, BALANCE & NOTCH.

      CLICKING ON NOTCH, OPENS UP A PANEL WHICH HAS THE
      FOLLOWING PARTS:
      BYPASS:
      HAS A PLACE TO CLICK TO ACTIVATE IT

      QUESTION:
      WHAT DOES 'BYPASS' MEAN IN THIS CONTEXT??

      CENTER:
      HAS A CENTER SLIDER TO ADJUST FROM - TO +
      THE DEFAULT SETTING IS 1,495.0 Hz
      QUESTION :
      WHAT DOES THAT NUMBER MEAN??

      Q:
      ALSO WITH A SLIDER TO ADJUST FROM - TO +
      THERE IS A DEFAULT SETTING OF "2.6."
      WHAT DOES THAT MEAN??

      CLICKING ON 'VOLUME' OPEN A PANEL
      WITH A SLIDER MORE OR LESS IN THE RIGHT-CENTER
      AND THE DEFAULT READING IS '0.0 dB.'
      AGAIN, WHAT DOES THAT NUMBER MEAN??

      I OBVIOUSLY NEED HELP WITH USING THIS TOOL,
      AS WELL AS SOME BASIC FUNDAMENTALS IN AUDIO
      NUMBERS AND IT WOULD BE APPRECIATED

      I READ THROUGH SOME FORUM THREADS ON HUMMING &
      IT WAS STATED SOMEWHERE TO DOWNLOAD "AUDACITY"
      WHICH I DID, BUT HAVE NOT YET TRIED TO USE.
      ANY HELP WITH THIS, IF I NEED TO USE THIS RATHER
      THAN THE ADOBE AUDIO TOOLS, WOULD BE APPRECIATED.

      THANK YOU.
        • 1. Re: Audio--Humming--How to remove
          Steve Grisetti Adobe Community Professional
          Ira, please turn off your caps. It's very hard to read a long post that's in all capital letters.

          Audacity is very easy to use. You will need to open the audio clip in Audacity so that you can use its notch filter. You can not do it in Premiere Elements.

          This filter can be set to remove sounds of a certain frequency. You should be able to set it to remove that hum -- but, of course, it will remove everything at that frequency and, if your hum as at the same frequency as some of the other audio, it will remove that also.

          Good luck with it!
          • 2. Re: Audio--Humming--How to remove
            the_wine_snob Level 9
            Ira, here are some answers to your questions:

            i Question: do you drag the "notch" icon to the clip in the sceneline or timeline, and do you drag it to the audio part or the video part or does it make no difference?

            All Effects work is much more easily accomplished in the Timeline and by using the Effects Panel.

            i question: what does 'bypass' mean in this context?

            Bypass means to skip this Effect (turn it off) for now. One could Keyframe it going from full to Bypass, if they wished to.

            i Center: has a center slider to adjust from - to + the default setting is 1,495.0 Hz. Question : what does that number mean?

            That number is the frequency range. Really good human hearing goes from about 20 Hz to 20 KHz.

            i Question: also with a slider to adjust from - to + here is a default setting of "2.6." What does that mean?

            That is the amount of increase, or attenuation, and is usually specified in db change.

            i Clicking on 'volume' opens a panel with a slider more or less in the right-center and the default reading is '0.0 db.'Again, what does that number mean?

            With the Volume slider at 0.0 db, there is no change. You can type in a positive number to increase the volume, or a negative number to attenuate the volume. If its set to 0.0 db, there will be no change. Also, you can drag your cursor across this number and increase (right), or attenuate (left) the volume that way.

            Audacity is a wonderful little freeware program that functions like a mini-Audition (Adobes audio editing/mixing program.), and it is quite robust. It has limitations, but hey, its free.

            For the removal of background noise, its really trial and error. You have to listen carefully, to all the changes and Effects that you apply and their settings. Use the Preview function often, and listen carefully - very carefully. As Steve points out, when you attenuate an audio signal in a certain frequency range (displayed in Hz) by an amount (displayed in db), you are doing this for every sound in that frequency range. That is why you need to listen carefully. Ive found that removing background noise can work effectively, but can also give a hollow, tinny sound to vocals. Be careful and listen very carefully. A good set of noise-cancelling headphones is really a must, so you dont try and eliminate sounds that are actually coming from your computer, your own AC, or your ceiling fan. Its partially science, but also an art.

            Last comment, there should always be some ambience left in the sound. You do not want it to be totally dead, unless you shot footage in a recording studio. If you have more hum, or other background noise, than you can safely remove via PEs Audio Effects, or programs like Audacity, you might want to purchase, or record, some room ambience tones, and place those an Audio Track in your Timeline. Many SFX discs have ambience tracks, and many are also available free, or for a fee, on the Web. There are also tutorials on the Web on noise removal. One place Id start would be:
            http://www.looperman.com/tutorials-production-17-compression_explained.html (watch for word wrap, as this is the full URL and not a TinyURL.

            Good luck,
            Hunt
            • 3. Re: Audio--Humming--How to remove
              MAMBO_MAN Level 1
              Thanks to both of you for your quick responses.

              Question:
              If I use Audacity, how do I go about copying the
              audio track in the video to the Audacity software
              program for editng??
              (step-by-step, please, if possible)
              In other words, since the audio & video are basically
              tied together in the .VOB files, how do you go about
              separating the audio out to copy to the software.

              Incidentally, I played with both the "center" and
              "Q" sliders, going to extremes on both sides, with-
              out losing the audio at all. Yes, some areas of
              changes sounded "tinny" but I could never complete-
              ly lose the humming sound.

              Any further tips appreciated.

              Thanks
              • 4. Re: Audio--Humming--How to remove
                PeterFDuke Level 1
                Hum is rarely a pure sine wave (single frequency). It usually includes harmonics. The hum is spurious pickup from the electricity mains, so the fundamental frequency will usually be 50 or 60 Hz, depending on the country, with harmonics at 100 (120), 150 (180), 200 (240), etc. in decreasing amplitude. However the ear becomes more sensitive with increasing frequency in this range, so the higher harmonics may be the ones you actually notice. Due to the way hearing works, you can even remove the fundamental and lower harmonics but it will still sound like 50 (60) Hz (although sounding "thin") because that is the spacing of the harmonics. For these reasons, the hum may not be made inaudible using a simple notch filter. You would have to use it multiple times at each harmonic frequency. The notch should be sharp (high Q) to avoid losing too much wanted audio.

                Once you have done that you could then use the normal noise reduction filter in Audacity to clean up the residual high harmonics.

                Someone else will have to help you with exporting the audio because my computer is rendering at the moment, and so I cannot check the precise steps. You need to set the Work Area Bar over the clip to be exported and export the clip's audio via the Files menu.
                • 5. Re: Audio--Humming--How to remove
                  the_wine_snob Level 9
                  Ira,

                  To get your Audio into Audacity, or any other WAV editor you need to choose File>Export>Audio, then Import that into your WAV editor. Choose the location to Export and leave the default type set to WAV. Lets assume that all you have in your Project right now, is your Audio on Audio Track 1 and Video on Video Track 1. If you have other Audio, ambience, SFX, etc., see the solution to that below.

                  If you do have other Audio Tracks, Id do this: File>Save a Copy. Choose a name that reflects what youre doing, i.e. setting this up for Audio Export. Open the Copy, and remove the other Audio Tracks, so all you have is the Audio, that you wish to edit. Do not worry about the Video, as youll not even need that. Use the File>Export>Audio, just as above.

                  One caveat: this should be just about the last step that you do in your editing. The reason is that unless your Audio Track, at this point, is only the original Audio from your footage, it will Export as one continuous file. It will include any edits that you have made to your Clips, but will still incorporate all your Audio into one file, not small ones that mirror your cuts, etc. If your source footage is un-edited, ignore this warning. If one does the Audio editing, before any cutting has taken place, theyre probably going to save a few keystrokes, BUT theyll be working with one long Audio file. If they wait, until the end of the Project, theyll be able to do several things, like make other Audio adjustments at the same time as the noise reduction and will only be working with one long Audio file, but it will be the exact length as the edited pieces. In the next step, theyll have to Delete more original Audio files, but dont have to worry about going back to do gain changes, etc. The choice is yours. I choose to do this at the end.

                  Once the Audio is edited, Save_As and give this file a unique name. Back in PE, Open your original Project (not your Copy), Import the Audio file that you did the Save_As (paragraph above), and then Alt-click on the Audio Track Clips, or Clip (depending on what you have done already in the editing process) and Delete. If you have more than one Audio Clip, you will need to do this for all. Now, from your Project Panel, drag your newly Imported Audio file and line it up with the beginning of the very first Video Clip. Here, Id do a Save_As, or Save a Copy, so you still have your original Project untouched, in case you have to go back to it.

                  The difference between Save_As and Save a Copy is subtle, but can haunt you, if you do not know it. With Save a Copy, you will be saving a copy, as the name implies, BUT you will still be working in your original Project. With Save_As, you will be saving a copy, BUT youll now be working in that Copy. Subtle, but important difference. I would use Save_As, so I could continue working seamlessly, but leaving my original Project untouched.

                  Before you apply this technique, Id immediately make a Copy of your Project, just for safe keeping, even though youll be doing that again, if you follow the steps above. You can never be too careful.

                  Note: in P-Pro Production Studio, one has many fewer steps, as a Rt-click on an Audio Asset gets a drop-down with Edit in Audition. This transfers the file and opens Audition. A Save from Audition automatically replaces the Audio Asset, leaving the original in the Project, but no longer on the Timeline. In PE, there is the Edit Original, but I cannot see how to link this with ones WAV editing program. There is nothing I can find in Edit>Preferences to set which other programs are used for various tasks outside of PE. Maybe someone else can shed some light on how to set this up, as it might save some steps.

                  If I have not made the steps clear, do not hesitate to reply and Ill try to explain it in another way. Also, if anyone has a more direct method, please share it.

                  Good luck,

                  Hunt

                  PS Peter, thank you for the useful explanation on the "hearing" of noise - in this case 50/60Hz hum.
                  • 6. Re: Audio--Humming--How to remove
                    MAMBO_MAN Level 1
                    Thanks again.

                    I'll give this a try & see (excuse me---listen)
                    what happens.

                    Any other tips & hints would be appreciated.
                    • 7. Re: Audio--Humming--How to remove
                      the_wine_snob Level 9
                      Ira,

                      Give us a shout back, as you progress.

                      Don't know if I mentioned a tip, but a good set of noise-cancleing headphones is a real plus for this sort of work.

                      Also, Curt Wrigley has a good tutorial on his site. It's meant for Audition, but other audio programs can probably be translated into this tut: http://www.wrigleyvideo.com/videotutorial/tutdes_audition_noisecancel.htm

                      Good luck,

                      Hunt
                      • 8. Re: Audio--Humming--How to remove
                        Level 1
                        Hi -- I have been reading this thread and have a related question.

                        I have a recording of an interview that should have been done with a lapel mike but was not and so there is some background noise. It's tolerable until the pop machine comes on and then that thrum is very loud. This sound does not show up as a separate track in PE. Do you think I will be able to edit it out in Audacity?

                        I tried playing with the various sound settings in Elements, but do not understand enough about what they mean or can do to use them competently. This interview cannot be redone and is central to a presentation.

                        Thanks,
                        Sue Hellman
                        • 9. Re: Audio--Humming--How to remove
                          PeterFDuke Level 1
                          Sue

                          Without hearing your case I can't say definitely whether Audacity will help much, but give it a try anyway.

                          It is practicable to reduce moderate noise to a lower level provided that it is steady. The louder the noise the less successful. Noise reduction methods we are talking about here may make the speech sound more pleasant but it won't improve the intelligibility (the human ear is apparently near optimal for extracting speech from noise already).

                          I am not surprised that you didn't get much joy with the noise reduction in PE. I couldn't either. I suspect that the algorithm was designed to remove hiss from audio tapes or surface noise from vinyl records, where the noise is more or less "white" or has higher energy in the higher frequencies. Ambient audio noise in video recordings generally has much more energy at low frequencies. Another problem I found was that my camera at the time recorded with a 32kHz sampling rate (bandwidth 16 kHz) but when imported into PE it gets converted to 48 kHz sampling rate (bandwidth 24 kHz), so there is no energy at all in the recording between 16 and 24 kHz, but the algorithm assumes that the noise is flat.
                          • 10. Re: Audio--Humming--How to remove
                            PeterFDuke Level 1
                            The best noise reduction tool I have tried is Izotope RX
                            http://www.izotope.com/products/audio/rx/
                            but at $349 it is not cheap. The trial version only has the limitation that you can't save your work. You might be able to record the sound you are listening to.
                            • 11. Re: Audio--Humming--How to remove
                              Level 1
                              http://videoinasnap.chuckengels.com/source/ken/cooltools_11-05.htm
                              • 12. Re: Audio--Humming--How to remove
                                MAMBO_MAN Level 1
                                Thank you Mr. Jarstad for that link to detailed instructions for
                                audacity. I'll give it a try in a bit.
                                • 13. Re: Audio--Humming--How to remove
                                  Level 1
                                  Thanks to everyone for replying to my posting about the thrum of the pop machine. I will be trying all solutions as well and will get back to this site when I have some results.
                                  • 14. Re: Audio--Humming--How to remove
                                    MAMBO_MAN Level 1
                                    Dear Mr Jarstad,

                                    A few questions:

                                    In the instructions in the linked article, you
                                    state:
                                    "Then use Alt-[ and Alt-] to set the WAB"

                                    What is the 'WAB'--I can't find it in the Adobe
                                    Premier Elements Manual or in the "Dummies" book.

                                    I did find a very small (1 or 2 seconds) "gap' of
                                    just 'hum' without any other audio & made sure I
                                    recorded the time of its occurence

                                    In any event, the audio hum I have is continuous,
                                    throughout the whole .AVI file, so I just used the
                                    page up & page down in Adobe Premier Elements 4
                                    [APE4] to have the CTI select the whole audio
                                    track; this yielded a .WAV file of 462 MB (The .
                                    AVI file was 8.9 gigs) saved in a different folder
                                    (than in APE4)
                                    Was I wrong do do this??

                                    You also stated in the instructions:

                                    "I find it easier to find a 'gap' in the audio by
                                    zooming in on PrEl's Timeline window. Make sure you
                                    see the audio waveform on the audio track."

                                    Where??
                                    In APE4 or in Audacity?? Or both??

                                    I opened up Audacity,
                                    Clicked On 'Project',
                                    Then on 'IMPORT AUDIO,'
                                    Then on the .WAV file I had copied from APE4 TO
                                    to a separate folder..

                                    I then got this error message:
                                    "Audacity.exe has encountered a problem and
                                    needs to close."

                                    I clicked on the area for further info (or
                                    details) and got:

                                    "ERROR SIGNATURE:

                                    AppName: audacity.exe AppVer: 0.0.0.0
                                    ModName: ntdll.dll
                                    ModVer: 5.1.2600.2180 Offset: 00011e58"

                                    I continue to get this message multiple times,
                                    even after I re-started windows.

                                    I've got about 75 gigs free space on the HD I'm
                                    using for this task.
                                    also 1 gig RAM & CPU = 2.4 GHz

                                    Any suggestions??

                                    Thanx
                                    • 15. Re: Audio--Humming--How to remove
                                      MAMBO_MAN Level 1
                                      Follow-up:
                                      For anyone who uses Audacity & has had problems
                                      loading an audio track into it, the following
                                      might be helpful.

                                      Under Audacity preferences--File Formats:

                                      "When importing uncompressed audio files into Audacity":
                                      Choices are:
                                      1) "Make a copy of the file before editing (safer)
                                      2) Read directly from the original file (faster)"

                                      I initially used the default (#2) & would ALWAYS run into
                                      the trouble I described previously (See below--would get
                                      error message & Audacity would have to close without load-
                                      ing any of the .WAV file into it).

                                      However, when I checked #1 (#2 automatically grayed out),
                                      ALL of the .Wav file loaded into Audacity (slower) without
                                      ANY problems.

                                      I can't explain this--maybe somebody else can!

                                      {I opened up Audacity,
                                      Clicked On 'Project',
                                      Then on 'IMPORT AUDIO,'
                                      Then on the .WAV file I had copied from APE4 TO
                                      to a separate folder.

                                      I then got this error message:
                                      "Audacity.exe has encountered a problem and
                                      needs to close."

                                      I clicked on the area for further info (or
                                      details) and got:

                                      "ERROR SIGNATURE:

                                      AppName: audacity.exe AppVer: 0.0.0.0
                                      ModName: ntdll.dll
                                      ModVer: 5.1.2600.2180 Offset: 00011e58"

                                      I continued to get this message multiple times,
                                      even after I re-started windows]
                                      • 16. Re: Audio--Humming--How to remove
                                        the_wine_snob Level 9
                                        Ira,

                                        Sorry that I cannot help here. I have used Audacity on occasion and have it on most computers, but use Audition for most of my audio work.

                                        Good luck,

                                        Hunt
                                        • 17. Re: Audio--Humming--How to remove
                                          MAMBO_MAN Level 1
                                          To Mr Hunt & all others interested in this subject-thread:

                                          Follow-up:
                                          Hi Ken:

                                          Under Audacity preferences-- File Formats:

                                          "When importing uncompressed audio files into Audacity":
                                          Choices are:
                                          1) "Make a copy of the file before editing (safer)
                                          2) Read directly from the original file (faster)"

                                          I initially used the default (#2) & would ALWAYS run into the
                                          trouble I described previously (would get error message &
                                          Audicty would have to close without loading any of the .WAV file
                                          into it).

                                          However, when I checked #1 (#2 automatically grayed out),
                                          ALL of the .Wav file loaded into Audacity (slower) without ANY
                                          problems.

                                          I can't explain this--maybe you can!
                                          --------------------------------------
                                          Hi Ira,

                                          I cannot explain the unusual circumstance either.

                                          One other thing to try:
                                          After reading in the file via choice #1
                                          save the file under a new name.
                                          Then start again but read in the new file.

                                          If that works then there must be something that hap-
                                          pens by opening and closing the file. Thinking about
                                          that for awhile, I recall that sometimes files don't
                                          get closed properly - they should have something known
                                          as an end-of-file marker - EOF.

                                          And since the EOF is standard, if the app finds the
                                          EOF is missing or corrupted then the app will append
                                          the EOF because it has to be there anyway. Speculation
                                          on my part, but I have read a few tech articles in my
                                          life!

                                          Glad to see that your persistence paid off.

                                          Ken

                                          Ken_Jaristad@bigfoot.com
                                          OR
                                          ken.jarstad@gmail.com
                                          • 18. Re: Audio--Humming--How to remove
                                            MAMBO_MAN Level 1
                                            Addendum:
                                            Further follow-up on Audacity:

                                            "Disregard my suggestion.
                                            I just re-read your earlier email and got some of
                                            the facts wrong. I meant option 2, but you said
                                            option 2 would fail, so my suggestion makes no
                                            sense!

                                            Your using option 1 solves the problem and
                                            that is that!

                                            Ken Jarstad"