Before our youngest children are ready to learn phonics, they need to be able to discriminate between the sounds around them. For our youngest and pre-verbal children we work on raising awareness of the environmental sounds around them. This is a really interesting a activity to do now as there is less traffic noise and more opportunity to listen to the sounds of nature.
Some activities you could try are:
Going for a listening walk and seeing how many different sounds you can hear
Use different household items to drum on to compare sounds. Kitchen pots and pans are great for this (honest!).
Make shakers using old plastic bottles and pasta, rice or lentils to fill them. Do they make different sounds when you shake them?
More information and activities can be found at http://www.letters-and-sounds.com/