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:
This was produced by tapping on a stethoscope which had an earbud pressed against a Shure SM57 mic. Low pass filter applied, as well as compression and a gate. Chorus added. Used a recording cassette deck as a preamp going into an M-Audio Audiophile USB soundcard. Note: If you're having problems listening to this clip, the cutoff frequency of your speaker set may be too high(solution: new speakers). The signal strength exists almost entirely in the very low frequencies, so you may need a sub-woofer to hear it. Otherwise, try turning your speaker volume all the way up. Doing so may saturate the signal and at least allow you to hear the harmonics of the signal caused by the distortion. I don't recommend it, but you'll at least maybe be able to hear something.