Mention adaptive audio to any group of game developers, and you will likely get quite a mixed bag of reactions from both positive to negative and everything in between. The reason for this has to do more with the definition of adaptive audio than what it means with respect to implementation. So, perhaps we should establish a proper definition of what is adaptive audio before we get too far into things. Here is a good broad definition of the term as it applies to modern game development:
"Adaptive audio" is a term used to describe audio and music that reacts appropriately to - and even anticipates - gameplay. Guy Whitmore (Gamasutra)
While that definition does sound somewhat abstract, it really does a good job of defining what adaptive audio is. It is audio that anticipates, adapts to, and reacts with gameplay in order to enhance gameplay. The critical word in that definition is gameplay and that is what separates it from dynamic audio. We will define dynamic audio...