Pull the file up in CE2.
Go to Effects, then Filters, Graphic Equalizer.
Going way off subject here,..because I am bored and recklessly assuming...
Now depending on WHY you want to muffle them, keep in mind that anything over 2k (frequency) doesn't make it through hard surfaces well. In fact the cut off rate for frequencies that can penetrate glass starts around 2k and goes up (to the right on the graphic).
The roll-off rate of those upper frequencies progresses as you go up the scale... In other words, unless it's like ripping the hair out of your scull (we're talking like 125-140db, 135 being the threshold of pain), it won't make it through glass easily.
I'm a concert audio engineer, sometimes when we do outside shows in bad weather we have to cover the stacks with tarps,...just simply plastic tarps. Sometimes the show goes on anyway and we have to blow that high-end treqs. through the tarps.
(low-end makes it through anything, 80hz being omni directional, the higher the frequency the more narrow the dispersion, the lower the more omni directional)
I have to almost triple the output of the high end to make it through a tarp and still sound good enough for meet the same levels as the low end frequencies. Ok now that's just tarp, mulitply that times say 7 for glass.
The reason I bring this up is if you are planning on making interior sounds you probably want to know what frequencies to start cutting off at. And remember, low-end omni direction make it through anything, it will be slightly exaggerated in the low-mids down as it resonates the frame of the ac, high-end (2k+) will diminish,... but NOT completely as there are some leaks through softer objects, air leaks etc...and there is a lot of kack in engine noise.
SO the rate will depend on exterior volume, material it is passing through, and proximity. Using engines for example; On large AC the engines are further away from you and passing through a more dense airframe, nor part of the same compartment. They might be quieter then then a smaller AC where the engine is a part of the nose you sit in.
Volume wise I always Normalize a file to -1 when I am done. In fact I pull the volume down to -3 to begin with as well so what I add does not make the file volume peak and distort. Anytime your green line (wave) flattens out at the top, there will most likely be distortion there (clip). Keep it down, then re-correct the volume to -1, this will leave some natural dynamics in the response rate.
Good luck, if you're making interior sounds out of exterior sounds,...it can be tricky to get "right", but definitely can be done\simulated.
If I am way off subject , maybe it will help someone else. <shrug>
$5 for aimless WOT.
Animl
