Website visitors leave voice messages for others

I would like to find out what it would take to allow visitors to my website to post audio files that other visitors could listen to. I think it would be something like what is found on metrodate com. The members are able to leave a recording and visitors can look at their ad and listen to their voice. I believe this is accomplished in flash. It looks like they allow you to upload a file and then will approve it. However, what I am looking for is a way for an user to record an audio while on the site and have it previewable and if it is what they want to have it posted on their page. So they click a record button, it records they click stop. they click review button and if they like it they click a POST button and it is posted. Please ask any questions about this and make any suggestions of the correct terms or software that would help in this project. This is the key part of a larger project that will happen if this type of upload system is possible. thanks for your time.