Editing Sound Effects in Audacity

[Syphex]

I'm brand new to editing sounds and I had a question about adding sound effects after editing them in Audacity. I purchased a couple of sound effects off the internet and made a very simple sample video in Windows Movie Maker. I first ran them in Movie Maker unedited and they worked fine. I then took them into Audacity and changed them to how I wanted them to sound. After placing them back into Movie Maker I noticed that they have a slight hissing sound. In Audacity the clips sound fine after editing. Its only when they are placed in Movie Maker edited that they make that hissing sound. Is there something else I need to be doing in Audacity when I'm editing these effects? Or is it the two programs I'm using?

Edit: It seems it could be my headphones.

 

[Zensteve]

When you make all your imports, exports & changes in between... are you keeping the same sample rate?

 

[Syphex]

I believe you were right about the sample rates. The original clip was at 44100 Hz. I made sure that the edited clip was at the same. However, Movie Maker still gave me that terrible hiss. So I kept dropping the rate until it was at a mere 8000 Hz. Nearly all the sibilance is gone in Movie Maker. In Audacity I'm not picking up any at all. The only thing I altered in this clip was the pitch. Its weird because if I use the clip as is and don't take it into Audacity I don't get any sibilance in Movie Maker. Its only after I transfer it from Audacity that I have this happen. The other sound tracks I have running with this one mask the little hiss that is left but I would really like to not cover my mistakes and just eliminate them instead.

Has anyone else had this problem with Movie Maker? I know its not a great program and my editor uses Pro Tools but I just wanted to try my hand at it.

 

[knightly]

Did you speed it up? when altering pitch, it'll alter even the room tone, which can go from a "normal" tone that your ears will just accept to a hiss as it is sped up.

I would recommend that you use the spectrum analyzer to look at the initial sound and make sure that's as clean as possible before doing the pitch shift on it... and the pitch shift plug-ins that keep the sound the same length do weird voodoo to make it do that. You may consider simply speeding up/slowing down the clip to shift the pitch instead of using a "pitch shift" effect. It may give you better results (although, it'll shorten / lengthen the clip respectively).

 

[Alcove Audio]

A common error when migrating audio clips between programs is not paying proper attention to sample rates.

Audio for Video is 48kHz. Audio for CD is 44.1kHz. Most audio editing programs (Digital Audio Workstations) are aimed at musicians, so default to 44.1kHz (unless you tell the DAW not to by setting up the session at 48kHz). When the modified/edited audio clips are re-imported into the NLE at 44.1kHz it is now at the "wrong speed" so to say.

So you should set up new sessions at 48kHz or export the audio clip(s) at the proper sample rate.

BTW, reducing the sample rate may reduce hiss but it also seriously reduces the quality - and it will be at the "wrong speed."

To reduce hiss you use a low pass filter. Start at about 10kHz and work your way down; be careful, however, of going to low because you will lose too much high end intelligibility. Dialog clean-up is an exercise in compromises.

 

[Syphex]

I went ahead and did what was suggested. I made sure it was set to 48kHz and for the most part the hiss is gone. I couldn't eliminate all of it without distorting the clip but the other audio tracks that I had to add to it such as walking and nature ambience have masked the little hiss completely. Even before that I could only hear the hiss through headphones. I am new to this and still need to read what all the tools can do not to mention the sound language in general.

Edit: I actually figured out how to get rid of all the hissing. I learned how to use the noise removal tool finally.

 

[knightly]

My youtube channel has a few audio how to vids... the last one is about audio cleanup using audacity.