the hiss that wouldn't die

Win 7 64-bit SP1, HP desktop, AMD dual-core CPU with Realtek HD Audio card; Audacity 2.0.2 from the .exe installer:

Any time I try to fade in from silence, fade out to silence, use the noise removal tool, or use the silence tool to erase, there’s a persistent hiss.
(edit: the hiss isn’t apparent during program, just in the moments when nothing’s supposed to be there.)

Despite all the things I’ve learned since Audacity 1.2.6, this problem persists.

I’ve changed the audio host from MME to DirectSound, and even changed the saved file from mp3 to AAC/m4a, and nothing helps.

I use this for restoring vinyl and cassette recordings, and even pre-mastering of my own original work.

I didn’t have this problem with v 1.2 when running Vista SP3 on my laptop. What’s the deal?

Could you be talking about dithering? Audacity adds a tiny bit of noise to exports to ease the transition from 32-bit floating to 16 bit PCM. You can turn it off in Edit > Preferences > Quality > Conversion. You may not want to because the distortion goes up when you do that.

I think that only happens on Export, so if you’re getting the noise while the show is inside Audacity, that’s probably not it.


Could you post a short sample (just a few seconds) in WAV or FLAC format to illustrate the problem. Please ensure that the sample includes some normal level audio and some of the hissy silence.

Koz: To clarify, there’s no noise inside Audacity, but when I export, there’s a small amount of hiss in quiet sections and at the tail end of fadeouts (or conversely, the head-end of fade-ins). I’ll try changing the conversion settings to see if that helps.

Steve, let me work on posting a short sample of my own original work (don’t want the brain police after me!). I will get back to you.

Is it possible the noise is coming from your soundcard? Do you hear the hiss when you pause playback?

I’ve listened quite closely, and the soundcard isn’t the culprit. It’s the stock Realtek unit that came with the desktop, but it’s pretty quiet.

Steve and Koz: I’ve reset the dithering to “none”, and based on some sample MP3 and AAC/m4a exports, that appears to have solved the issue.

Ding-dong, the hiss is dead!