Audacity Forum

I'm trying to reduce a significant hiss in a voice-over recording. If I select a segment containing noise, generate a noise profile, and then, without changing the selected segment, run noise reduction, I get a nice result; but it if I change the selection at all, I get bad electronic artifacts.

<<<significant hiss in a voice-over recording.>>>

The tools are designed to suppress "background" noises like minor air conditioning noise or microphone hum. By the time you get to "significant" problems, you lose the ability to separate the trash from the show -- especially with hiss which is impossible to do anyway.

The sample or profile system is extremely sensitive. You need to take a noise sample with no show or voice at all. The tool will try to subtract the "personality" of the sample from the total performance. If the sample has the slightest amount of voice, you're dead.

Some of the elves recommend that you amplify the selection, take the sample, and then reduce the volume to normal. This seems to help the profile process.

You also get to mess with the three adjustments. They make a big difference. Never apply more correction than you absolutely need.

Hiss is rough. The tools try to choose which frequencies are in the interference so they can subtract them from the show and hopefully, nobody will miss them. Hiss has all audible frequencies. So now what? You can't take them all out, there will be no show left. Some of the more successful tools try to figure out which sounds are words and give those sounds a special pass. Sometimes those tools give you words with hissy tails on them. Hellosss. Howss Aress Yousss?

You have a very serious problem.

Koz

akline wrote:I'm trying to reduce a significant hiss in a voice-over recording.

The sound cards that are built into most PCs are not designed for high quality recording. Playback is usually reasonable, but microphone recording is generally telephone quality at best. Recording at a reasonably high level can minimise the hiss (but take care not to record too loud or it will distort) and using a little noise removal can make a bit more improvement, but it's not possible to get high quality microphone recordings without using a reasonably good microphone and sound card.