Following up, we encountered some strange behavior when we tried to solve this issue — sometimes it would let other people successfully upload the data to our server, but we were only able to do it when their browser said that it did not trust the SSL certificate.
It is worth mentioning that we are using the PCIbex farm to run our experiments. Our server has a self signed certificate, which the browser flags as invalid. We are wondering if the Media Recorder element requires specific browser settings/configurations for Firefox and Chrome? I am always able to upload the audio files when I use Firefox on my computer, but can’t do it when I use Chrome. Other people are not able to do this even if they use Firefox. Any help would be greatly appreciated.