Audacity seems to be super self-explanatory; you click the effect you want, a dialog box prompts you to enter a few settings, and voila! But those settings aren’t always immediately obvious. So to save you the trouble of having to figure out the settings on the echo effect, here’s a brief tutorial.
For fun, I chose a gavel sound from freesound.org to work with. Below is a picture of what it looked like in audacity before I did any editing.
It was pretty quiet, so first thing I did was amplify it. In case you haven’t found that yet, highlight the area you want to amplify (click and drag using the selection tool), click “Effect” at the top, and then “Amplify.” The following dialog box should appear:
The number you want to watch is the “New Peak Amplitude.” If it’s at zero, then you’re not amplifying the sound at all. Positive numbers make the sound louder, negative sounds make the sound quieter. Also, make sure you check the “Allow clipping” box if you’re making it louder; otherwise you won’t be able to apply the amplification. Below is a screen shot of the settings I applied to the gavel noise, followed by the new audacity graph (I only amplified half the piece for comparison purposes as I was working with it).
Now for the echo! Keeping that section highlighted, go to “Effect” again, and click “Echo.” You’ll get the following dialog box:
Delay time is fairly self-explanatory. It’s just how long of a time you want between the original sound and the first echo, and then in between all the echoes (the effect applies multiple echoes). You’ll need to adjust this to fit the time span of the sound you’re echoing. The default time is one second—too long for the gavel noise which lasts less than half a second. I would say that most of the time you probably want the delay time to be less than the time it takes for the sound itself. So I dropped it down to 0.08 seconds.
Decay time is basically how loud the echoes are. The echo gets quieter and quieter as time goes on, as echoes should, but you can still adjust how loud it is to begin with. The higher the number you put in for the decay time, the louder the sound; the lower the number, the quieter the sound.
Below is an image of the new audacity graph. If you scroll up and compare it with the other graph, you’ll notice that there are more “peaks” now. Each one is an echo.
What I discovered that was really neat about the echo effect is that it can make a noise sound fuller rather than just giving it a straight echo. Every time there’s a noise, there’s an echo. We just don’t always realize it because it’s not often very distinct from the noise itself. But using the echo effect, you can give a sound much more depth.