What is a quick and dirty way to put in a filter and in two signals for a hearing loss presentation? I want to take a song, say an mp3 of Louis Armstrong's What a Wonderful World, and I want to add a 30 dB reduction to mimic a 30 dB hearing loss. I then want to add in a +5 db signal at the 2000 Hz range and a white noise signal. How could I do this so that I could demo it in a presentation for diversity at work. Thanks!
I don't know if this will satisfy the "dirty" part, but you could use a free (freeware/open source) digital audio editor to get it done quickly and cheaply.
I'd suggest using Audacity. It's a popular, and in my experience, capable open source digital audio editor, which, with a little direction, you could quite easily utilize for all your needs. And because Audacity is popular, there are numerous online documentation, help videos and guides to give you that direction.
I haven't currently got this installed on any of my machines(although I used to), but looking at the built-in menu page from the digital manual, you have a few options to apply the effect you want, plus Audacity includes a white noise generator.
I'm pretty sure you can use any of these 'built-in' effects to acheive the adjustments you described:
*Classic Filters is not loaded into the Effect Menu by default but you can use 'Add / Remove Plug-ins...' from the Effect Menu to load it if required.
†Nyquist effect(Nyquist is a programming language).
Another plus for Audacity is the fact that you can easily implement VST plugin effects. I'm not sure if you know this, but VST(Virtual Studio Technology) enables the use of third-party effects. You can find many free VST equalizers and filters online.
Bear in mind, that you don't have to open Audacity or any other audio editor during the presentation. You can, instead, add the desired effects to the audio files via the chosen method before hand, then render/export the audio file and just play that exported file during the presentation.