Do you remember when PC games had more audio options than volume sliders and basic speaker channel output? Scalability options like being able to choose which API you could utilize. Options like DirectSound3D, EAX, OpenAL, and Aureal for the high end users with expensive sound cards. Also, options like DirectSound3D Software, Miles Positional 2D, and OpenAL software for low end users. Options like the amount of channels that could be processed (number of sounds that could be heard simultaneously).
I remember playing Halo Combat Evolved for the first time with my Soundblaster Audigy4. Granted the game only used EAX 2.0, which any HW sound card supported at the time. I was playing the first mission on the Pillar of Autumn. When I got up to the corridor right before entering the bay room where Covenant ships are docking and unloading soldiers I was dumbstruck. I was still around the hall to that room, but could tell exactly where some Grunts were located based on their sound alone. I knew where they were from previous play-throughs of the game. That's why when the actual 3D position of the noise was revealed I was struck. The position of the sound was about 99% correct. I could play this game blind-folded.
I remember playing Warcraft III in like 2003 (back when Warcraft was a real-time strategy game). I had options of Miles 2D, EAX 2.0, and Dolby. That's a lot of options for an overhead RTS game.
I remember playing an old game. This was a pretty popular title in the day. GTA 3. It also had many audio API options. My favorite was Aureal 3D. This is absolutely the best HRTF I've ever heard in my whole life. GTA 3 became real with a pair of headphones and Aureal 3D. Your fps took a real nose dive though. Wonder what it would be like on a modern PC? Maybe I should try? What ever happened to that API? Well, Creative Labs bought it up, took the tech and IP and locked it up in a dungeon with Goro defending it's exit.
There were also games that advertised the usage of modern API effects, but failed to deliver with half-hearted implementation of the features such as Rainbow Six 3.
Then came Windows Vista. Vista began a new era of Windows operating systems (Vista/7/8/8.1/10). They differed enough from the previous versions of Windows OSes from the fact there was no longer a HAL (hardware abstract layer). Audio API's such as DirectSound3D depended on it. EAX depended on DirectSound3D. And began a trend.
Vista and newer still had hardware support for OpenAL. Creative Labs even made a wrapper called Creative ALchemy which would translate DirectSound3D and DirectSound3D dependent EAX code into OpenAL for hardware support. While it did work, the EAX in OpenAL was not as good as the EAX for DirectSound3D. This was an issue for those of us that noticed it. Playing an EAX game dependent on DirectSound3D sounded much better than playing an EAX game dependent on OpenAL.
Later on into the late days of Windows 7, OpenAL became more software oriented and improved somewhat on the quality front. Some people including many respected developers and programmers would say the new software OpenAL is actually better than hardware EAX w/DirectSound3D. Which may be true. Only problem is it is all CPU dependent and will effect performance. XAudio2 stuff won't hurt performance even on outdated CPU's. New-age OpenAL DSP stuff will harm performance even on modern CPU's.
Upon the release time of Skyrim I 'upgraded' my Audigy4 to an X-Fi. Turns out the X-Fi's while having support for EAX 3.0/4.0/5.0 did not have support for EAX 1.0/2.0 and thus these games are gimped EAX-wise. Skyrim has nothing to do with this. It's just a reference of timeline here in my story. Skyrim instead uses the modern Xbox 360/Windows audio API, XAudio2.
XAudio2 is a cross-platform audio API that makes porting easier. It's easier to setup. It's easier to make games for that even have 5.1 support. It works on any audio chipset because it's all software. It has much better latency than PCI sound cards. It's rendering quality is really clean, crisp and overall good like hardware DirectSound3D. Problems are: It's all software (most games limit channels to 32 or less). It's 5.1 support is only on par with Miles 2D positional audio (low-end multichannel). It's reverb effects consist of muffling, echo, louder echo, and obnoxious bass-stuttering echo. The last sound card I heard of that only has hardware support for only 32 channels was the Soundblaster 16 (circa: 1992-1999).
I remember playing a really old game, Vampire the Masquerade: Redemption, made in 1998-1999. I had options to choose 7 different audio API's, including EAX 2.0. The fact that a game made in 1999 has better audio options (and quality) than any game made in 2013 - 2015 means we have truly taken a step back. There have been some redeemers such as Razor with their version of OpenAL (in software only DSP effects). At least the performance impact wasn't as bad as Aureal 3D was on Pentium III and IV machines.
Microsoft is supposed to be making a new XAudio API that supports hardware acceleration. They call it something else for XAudio, but regardless, the info about it had been around for years with no realization of it.
Remember when games used to sound better?