xanderK has posted in General Discussion regarding the issue.
Originally Posted by xanderK
Let me start off by saying that we apologize that this type of response took so long to make. Work on fixing this unforeseen issue began immediately after the sound issues surfaced. We expected that your enjoyment of our game would not be interrupted but sadly that was not the case. This issue was far more complicated than we could imagine and we wanted to get to the bottom of it and ensure that an acceptable solution would be reached.
After a tremendous amount of testing and many unsuccessful fixes, the issue with the Mac sound bug comes down to this: the primary sound library that Heroes of Newerth uses for all other operating systems does not work with Lion. The issue is so integral to how sound works in our game that it could not be fixed by any normal means. Instead, we were forced to use an unusual fix. This was a huge undertaking and after more than a month of hard work, it's nearly completed.
We have written our own secondary sound library for our Lion users.
Most importantly, this means that the game will sound the same as it did before. In addition, there are some added benefits to fixing the issue in this way.
This is a brand new open source library, meaning that we have much more control over the sound in our game.
The new library will be included in the client as an option to all users and can be used instead of the current one on all operating systems. Of course, for Macs, this will be the default setting.
We are extremely happy to bring this solution to our players and to fix this problem once and for all. Again, we greatly apologize for all the issues that this problem caused and will continue working to ensure that our players have the best possible experience with Heroes of Newerth.
We are trying to get this fix out to our users as soon as possible. Our Mac users can look forward to having their game back to normal in the near future!