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Help with background noises~

I'm volunteering as a research assistant for a lady who needs help with a few audio files. Basically, she has these audio files that are in WMA format and needs them to be converted to MP3. I found a free program on download.com that converts the file to MP3, but it takes a long time. For a file thats about 45mb in WMA format, it takes a bout 15 minutes to convert to MP3. Is there a program that might be quicker in coverting over to mp3? Or does it all depend on how good your processor is? The reason why I ask is because in order to open the audio files with audacity, the files must be in a mp3 format.

Secondly, the research lady wants me to find a program that can help her get rid of the distortions in the audio files and amp up the background. She gave me a sample to listen to, and the audio was so low! I can hear her fidgeting more than the person talking in the background. Most people would like to noise cancel the background, however, I'm trying to amplify the background so that we can hear what the people in the background are saying. I tried using audacity and simply raising the decibels. It kinda helped  but the fidgeting of the microphone was too loud to bare. If anyone could help, that would be awsome! I'm a complete noobie at this, and I'm trying to pick up this whole editing audio stuff! Thanks.

Help with background noises~

Reply #1
These WMA seem awfully large for garden variety tracks. Are they WMA Lossless? Are these tracks abnormally lengthy?

Yes conversion rate usually depends on the hardware (aside from length of the audio), but also the efficiency of the converting tool. If it was using LAME, it should be real quick. In my opinion, your converter is far too slow for modern technology, thus is either: (a) working with copy protected WMAs, (b) working on a slow system, or © poorly written. For conversion, I use Foobar2000. Last I checked, it plays and converts (unprotected) WMA lossless.

Audacity can open more than just MP3. As far as I know, it has always worked with uncompressed WAV, and the latest works with FLAC [HA-Wiki] [Homepage].

As for the rest of your post... I can't help you. I haven't done much with sharpening and cleaning up audio files.
OP can't edit initial post when a solution is determined  :'-(

Help with background noises~

Reply #2
These WMA seem awfully large for garden variety tracks. Are they WMA Lossless? Are these tracks abnormally lengthy?

Yes conversion rate usually depends on the hardware (aside from length of the audio), but also the efficiency of the converting tool. If it was using LAME, it should be real quick. In my opinion, your converter is far too slow for modern technology, thus is either: (a) working with copy protected WMAs, (b) working on a slow system, or © poorly written. For conversion, I use Foobar2000. Last I checked, it plays and converts (unprotected) WMA lossless.

Audacity can open more than just MP3. As far as I know, it has always worked with uncompressed WAV, and the latest works with FLAC [HA-Wiki] [Homepage].

As for the rest of your post... I can't help you. I haven't done much with sharpening and cleaning up audio files.


Thanks for the quick reply. Using foobar would that be the quickest way to convert from wma to mp3? I believe the files are somewhat lengthy, but are < 1hr.
Hopefully someone can reply soon with helping me with the background.

Help with background noises~

Reply #3
Quickest, way? I do not know. It is fast since it decodes it as fast as it can and (in the case of the LAME encoder) pipes the data straight into the encoder, thus avoiding the need to create a temporary file.
OP can't edit initial post when a solution is determined  :'-(

Help with background noises~

Reply #4
Hm. I'm guessing a simple noise reduction won't work?

Help with background noises~

Reply #5
.
If you cannot find the tools in the otherwise excellent Audacity application, download the free / evaluation edition of Adobe Audition III.  It sports a few more tools and interesting methods of implementation of said tools... and heck, for a short time at least, it’s free!

http://www.adobe.com/products/audition

Andrew D.
www.cdnav.com


.

Help with background noises~

Reply #6
1.  Download and install dBpowerAMP Music Converter.

2.  Download and install the Windows Media Audio 10 codec.

3.  Download and install dBpowerAMP DSP Effects.

4.  Right-click on a file you want to convert/fix, and select "Convert To".  This will open the dBpowerAMP Music Converter window.

5.  At the top of the window, select "mp3 (Lame)".

6.  Select your desired Output Location.

7.  At the bottom of the window, click "Add" -->  "Add DSP Effect" --> "Graphic Equalizer".  You can use the Graphic Equalizer to try to "tune out" the microphone noise if the noise and the voices you want to hear are at different general frequencies.  Usually noise as you describe will be at a higher frequency than the content you want to hear, so try turning down frequencies above 2000Hz (2 kHz) and turning up frequencies between 500Hz and 2000Hz.  These are just initial guidelines, so if these EQ settings don't work, feel free to try others.

8.  To boost the overall volume of the recording, select the DSP effect "Volume Normalize", then configure it to boost Fixed Amplification.  I'd recommend adding 6dB at first, which will make the sound considerably louder than the original.  If that's not enough, you can go as high as 12dB.

9.  Click "Convert >>".  This will convert the file to the MP3 format, place the converted file in the location you specified, and apply the DSP effects you configured.

There may also be other DSP effects that can help reduce noise and boost desired sounds in the recording.  Feel free to try out others from the "Add DSP Effect" list.  To remove an effect, right-click on it in the main window and click "Remove Selected".

If you find a good formula, then dBpowerAMP Music Converter will automatically remember all your settings the next time you want to transcode a file to MP3.  Just right-click on an audio file and select "Convert To", and the window will appear just as you left it last time.

I hope this helps.

Help with background noises~

Reply #7
It absolutely make no sense to transcode to mp3 for editing in Audacity- just decode the original file to wav. As to the rest of your post, you should be able to do that in Audacity.

Charles

Help with background noises~

Reply #8
It absolutely make no sense to transcode to mp3 for editing in Audacity- just decode the original file to wav.
Agreed.
OP can't edit initial post when a solution is determined  :'-(

Help with background noises~

Reply #9
You are somewhat mistaken about Audacity opening mp3 files. WMA and mp3 are both lossy compression formats. Audacity opens only uncompressed files. It can recognize some forms of lossy compression and decode them to wav in order to open them, but it has not, and can not, actually open the lossy compression files.

By converting from WMA to mp3, you are first decoding to wav, then encoding to mp3. This second step somewhat reduces the audio quality (or rather more than somewhat, depending on parameters). It takes perhaps twice as long as simply decoding the WMA to wav (and it makes the audio worse). Then Audacity has to spend a significant amount of time decoding the mp3 back to wav before it can start loading the file into itself.

If you simply set things up to decode the WMA to wav, then open the wav in Audacity, you will get the maximum audio quality possible from the source WMA, and you will spend the least amount of time converting between formats.

Help with background noises~

Reply #10
[quote author=AndyH-ha link=msg=547973 date=1203281306]You are somewhat mistaken about Audacity opening mp3 files. WMA and mp3 are both lossy compression formats. Audacity opens only uncompressed files. It can recognize some forms of lossy compression and decode them to wav in order to open them, but it has not, and can not, actually open the lossy compression files.

By converting from WMA to mp3, you are first decoding to wav, then encoding to mp3. This second step somewhat reduces the audio quality (or rather more than somewhat, depending on parameters). It takes perhaps twice as long as simply decoding the WMA to wav (and it makes the audio worse). Then Audacity has to spend a significant amount of time decoding the mp3 back to wav before it can start loading the file into itself.

If you simply set things up to decode the WMA to wav, then open the wav in Audacity, you will get the maximum audio quality possible from the source WMA, and you will spend the least amount of time converting between formats.[/quote]

Thanks for the tip. I guess I will try converting it directly to .wav instead of MP3. I will also try, like another user on here suggested, to change the frequencies. I believe he/she said that the background and the outside are two different frequencies, and that I can raise the freq in the background and lower the outside noise using the dbpowerAMP graphic equalizer. I hope that works!

Help with background noises~

Reply #11
Undesired noise and the target content are often within different frequency ranges in my experience - at least with hidden mic recordings I've made in the past - but this is not always the case.  I've usually been able to use the equalizer as described to "bring forward", so to speak, the sounds I want to hear.  The few times this didn't work for me, I had to take additional steps, either with other DSP effects at transcode time or with an audio editor after converting the file to WAV.

I just recommend the EQ/transcode approach as it's easy, and is usually a good first step to try.  Just make sure you DON'T delete the source file in the process; in fact, make a secure backup of it before doing anything.  (I'm sure you've already thought of this and done it, but it's worth mentioning.)

Also, the method you need to use will differ based on whether you just need to make the desired content reasonably audible (e.g., for manual transcribing or legal evidence) or need to produce something more refined (e.g., for publishing).

From your original post, it seemed to me like you just needed the target sounds to be more clearly audible, hence my recommendation to use dBpowerAMP to adjust frequencies, normalize the volume and get it into an MP3 format in (essentially) one easy step.  If you need to refine the resulting output more thoroughly, then of course you'll need to take further steps using a waveform editor such as the afforementioned Audacity.

NOTE:
Before embarking upon my approach, you can test it to determine whether it'll even be worth trying.  Play the original sample in an audio player with an equalizer, and adjust the EQ as I described earlier.  If that doesn't work, play around with the sliders any way you like until the sounds you want to hear are emphasized to your taste.  Then set the EQ in dBpowerAMP similarly when you use it to transcode to MP3.  However, if there's no way you can equalize the recording during playback to bring out the target content to your satisfaction, then my idea will not be the one to use.

Help with background noises~

Reply #12
[quote author=S-12 link=msg=548019 date=1203307489]Undesired noise and the target content are often within different frequency ranges in my experience - at least with hidden mic recordings I've made in the past - but this is not always the case.  I've usually been able to use the equalizer as described to "bring forward", so to speak, the sounds I want to hear.  The few times this didn't work for me, I had to take additional steps, either with other DSP effects at transcode time or with an audio editor after converting the file to WAV.

I just recommend the EQ/transcode approach as it's easy, and is usually a good first step to try.  Just make sure you DON'T delete the source file in the process; in fact, make a secure backup of it before doing anything.  (I'm sure you've already thought of this and done it, but it's worth mentioning.)

Also, the method you need to use will differ based on whether you just need to make the desired content reasonably audible (e.g., for manual transcribing or legal evidence) or need to produce something more refined (e.g., for publishing).

From your original post, it seemed to me like you just needed the target sounds to be more clearly audible, hence my recommendation to use dBpowerAMP to adjust frequencies, normalize the volume and get it into an MP3 format in (essentially) one easy step.  If you need to refine the resulting output more thoroughly, then of course you'll need to take further steps using a waveform editor such as the afforementioned Audacity.

NOTE:
Before embarking upon my approach, you can test it to determine whether it'll even be worth trying.  Play the original sample in an audio player with an equalizer, and adjust the EQ as I described earlier.  If that doesn't work, play around with the sliders any way you like until the sounds you want to hear are emphasized to your taste.  Then set the EQ in dBpowerAMP similarly when you use it to transcode to MP3.  However, if there's no way you can equalize the recording during playback to bring out the target content to your satisfaction, then my idea will not be the one to use.[/quote]

Eventually, the lady would like me to transcribe the audio for her. She wants me to cut the segments into small peices so that I'll be able to transcribe. I don't think transcibing would be that difficult, as long as I get a clear audio in the background. Actually, here's a sample of what I'll be dealing with. I asked her to send me the file so that I can look at it and see if it's even do-able.
sample clip

Help with background noises~

Reply #13
That's...wow. If this sample is representative of the rest of the recordings, then you're looking at a lost cause here. I can clear up a fair amount of noise and make her voice stand out a bit, but I can't really make out anything else enough to be able to 'work it out'. This noise is broad-spectrum, so it's really effective at masking any low-amplitude content.

If it's below the noise floor, that's it. Turn up the volume and do the best you can.

Help with background noises~

Reply #14
Wow - that's a challenge.  As you say, the noise level is very high and the speaker's voice is relatively quiet.

I used the transcode/DSP method described above using dBpowerAMP Music Converter, and uploaded the encoded result here.  (Also note the setting details in that post, as well.)

The noise is still prevalent, but not as much so as in the original recording, and I was able to pull the voice above most of the noise (I believe) well enough to transcribe.  If most of the rest of your recording(s) are at an equal or higher recording quality than this one, then this approach may work well enough for you to be feasible.  (It's main advantage being essentially one step to improve the voice clarity and transcode to MP3, as these are your main goals.)

Note that (to keep the uploaded file size reasonable) I had to transcode from MP3 to MP3, and you or she (I assume) had previously transcoded it from WMA to MP3.  That's lossy-to-lossy-to-lossy, so the sound quality may suffer additionally just from that.  If you use this method starting with the original WMA file(s), then you may get a slightly better result than the one I uploaded.  (At least it won't be any worse.)

Let me know what you think.

Help with background noises~

Reply #15
[quote author=S-12 link=msg=548226 date=1203392778]Wow - that's a challenge.  As you say, the noise level is very high and the speaker's voice is relatively quiet.

I used the transcode/DSP method described above using dBpowerAMP Music Converter, and uploaded the encoded result here.  (Also note the setting details in that post, as well.)

The noise is still prevalent, but not as much so as in the original recording, and I was able to pull the voice above most of the noise (I believe) well enough to transcribe.  If most of the rest of your recording(s) are at an equal or higher recording quality than this one, then this approach may work well enough for you to be feasible.  (It's main advantage being essentially one step to improve the voice clarity and transcode to MP3, as these are your main goals.)

Note that (to keep the uploaded file size reasonable) I had to transcode from MP3 to MP3, and you or she (I assume) had previously transcoded it from WMA to MP3.  That's lossy-to-lossy-to-lossy, so the sound quality may suffer additionally just from that.  If you use this method starting with the original WMA file(s), then you may get a slightly better result than the one I uploaded.  (At least it won't be any worse.)

Let me know what you think.[/quote]


Lol, thanks for the help. Transcribing is a very difficult job! The background does sound louder, however the outside noises are even louder. But I mean there isn't much you can do. it does sound a lot better, though. Ugh, she needs to record better!!
I listened carefully and it sounded like the lady said , There are fun activities to try when travel around the world. How can traveling the world be fun? ::Writing on the chalkboard:: Notice that I didn't give _________________.  i get lost from there. the topic here is traveling the world. what is the focus? i'll use your settings, s-12. thanks!

Help with background noises~

Reply #16
No problem.  That's why we're here. 

Actually, I was able to transcode the following:
Quote
There are fun...fun activities to try when you're traveling alone.  How can traveling alone be fun?  Is traveling alone fun?  <barely audible>How can traveling...<inaudible>.  Notice that I didn't give us any...<inaudible>...when traveling in groups, 'cause usually traveling in groups is more fun than traveling alone, so the more the b(etter?)... The challenge is traveling alone.  The "how" question...focuses on, uh, on the process.  Alright?  So the topic here is traveling alone... <inaudible>.  Um...what is the focus...<inaudible>...going to talk about everything about traveling alone, but you are going to be focusing <end of recording>

I had to listen in "short bursts", and go back every few seconds to repeat each section for as much clarification as I could get.  But I can definitely make out a lot more of the adjusted recording than I could of the original.

Sorry I couldn't do more with it.  Note that I am NOT a noise reduction expert by any means - there are several people here that know much more than I do in this area.  My recommendation just comes from how I've improved the basic quality of lecture and training session recordings over the past few years in one step using the dMC transcoder and it's add-on effects.

There are surely ways to get a better quality result, but I fear that the complexity of such a method may outweigh the value of the quality gained.

Help with background noises~

Reply #17
No advice on audio...but I wouldn't mind hearing the content if you get to the bottom of the audio problems.

Sorry for the sidebar......carry on.....

Help with background noises~

Reply #18
Okay! =) I finally learned how to the whole editing of the audio clips. My research lady assigned me a clip to listen to, but it's SO hard. I'm trying to hear the girls first, and then the guys in the background. But the guys in the background are too difficult to here. There's three/four different girls and I'm just trying to write down anything they say and then put who says what later on. This is the best I can get. May someone with better ears  listen to the audio file really quick and see if they can pick up any of the words or sentences I couldn't get?

http://www.fileden.com/files/2007/12/12/16...08%29covert.mp3

Here's all I got :

"The translation of the tradtional way to the western way but then__ doesn't talk much about that so I dont know.But  probably the conclusion talks more about like what the writer wrote in the body paragraph rather than talking more about the___ business.

And ugh __________And she's making a story book of [ratio] or she's describing her _____________.

The first line?
the first line?
cause like its not a personal  fulfill up but then its like because __________________

but its like husband, yes, __, like they are parents, like they

shes stuck in four years ago just where arrangement of families are from. you think?

like how different marriage is a form of the past and how women were different than us

teacher : it does say expections in the ________
yea.
so how about the conclusion?
yeah?
whats that?
conclusions is that um,
yes i answered yes.
i should, ugh, i think three.
teacher: how do we make it ___
we just it is like it is complimentating the sentence structure. directly answering the problem.
teacher: number one "

Help with background noises~

Reply #19
 The noise reduction is a new topic for me and that is why it is interesting to me also.
I could try to implement in a program some noise reduction methods for us to see the results.

 
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