Automatic Level Control (ALC) PulseAudio + LADSPA

Install:

sudo apt-get install swh-plugins

Run:

pacmd list-sinks|grep name:

It will report your output device name.

Mine in this example is:
name: <alsa_output.pci-0000_00_1b.0.analog-stereo>
Paste the text in bold from your results, replacing the * below:

pacmd load-module module-ladspa-sink sink_name=ladspa_sink master=* plugin=dyson_compress_1403 label=dysonCompress control=0,1,0.5,0.99

It's important you execute the command above on one line, no word wrap.
Put the whole line in a script, make it executable and make it part of your "Startup Applications".
Go to your "Sound Preferences", click the "Output" tab and choose the LADSPA plugin you just added.

This is the bare minimum of information you require to make this function work. I hate long drivelling posts.