Here is a simple guide on how to load and start using ERA Voice Changer audio effect plug-in in REAPER:
1) Verify that the plug-ins are installed in the correct locations
AU ➝ /Library/Audio/Plug-Ins/Components
VST ➝ /Library/Audio/Plug-Ins/VST
VST(64-bit) ➝ C:\Program Files\Steinberg\VstPlugins\Accusonus
2) Open Reaper and create or open a project from the file menu
3) Create an audio track by selecting from the menu Track ➝ Insert new track (omit this step if its a preexisting project)
4) Open the mixer by selecting from the menu View ➝ Mixer
5) Locate the Track Insert FX slots section on the top part of the mixer view, and click on a slot to open the new FX window.
6) Browse and load Voice Changer by double-clicking on it.
Done! Now you are ready to start using your plugin!