This is an example file for an HTML5 Audio and Video tutorial: HTML5 audio and video
Look at the source if you don't want to read the EduTechWiki article ...
This example should work in most current modern web browsers, since it defines the three most popular alternatives. However, defining a container format may not be enough, since each container may include different codecs. I.e. there are '''many''' codecs, in particular of WAV/PCM
Playing sound when a web page loads is not always appreciated. Use it sparingly. You might add some simple noise controls for the user. Of course you can rename the button text and put these anywhere you like.