Python: How to access variable declared in parent module

Using the structure from the Python docs:

sound/
  __init__.py
  effects/
          __init__.py
          echo.py
          surround.py
          reverse.py

Say I want to import sound.effects and get a list of available effects. I could do this by declaring a module-level variable in sound.effects and then appending to it when each .py file is imported. So sound/effects/__init__.py might look like this:

effectList = []
import echo
import surround   # Could write code to import *.py instead
...

From my main code I can now access sound.effects.effectList to get a list of effects, but how do I access effectList from within echo.py to do the actual append? I'm stuck trying to get access to the variable:

# None of these work :-(
# from . import self
# from .. import effects
# import sound.effects

sound.effect.effectList.append({'name': 'echo'})