On GotSound.org we are using wavesurfer.js to play sounds in a browser.
It's works only in modern browsers supporting Web Audio.
MediaElement fallback to support old browsers like Internet Explorer not always works.
You can find more information about browser supported Web Audio API here.
Please, consider to upgrade your browes to one of the following:
Another smashed lightbulb. I've actually made much more glass breaks in the past, but I've never bothered to upload them yet. Recorded with my Samson C03U microphone.