Which version of Windows are you using?
Which games are you playing (I'm assuming this is redbook audio you're talking about)?
Per above, can we assume you have an audio cable coming from your CD-ROM to your sound card?
Does your CD-ROM have a volume dial on the front (some of them did back in the day)?
Are you using the advanced audio mixer and have you tried reducing the slider associated with CD Audio?

Running Windows 10

In this case, most recently have played Recoil, and Klingon Honor Guard, but I noted that in other games that were from the era, they were the same

Yes, it is Redbook I'm talking about, other guy seems to have missed that

No, nothing like that, it is a modern DVD ROM drive, in previous version of Windows with much the same arrangement, I could adjust CD audio, I believe you still could in XP?

That is the point... There is NO slider anymore for that in modern Windows

CD Audio volume control in Windows has been crippled since Vista or W7 because of all the changes they made to how audio is handled.
It was never fixed, games stopped using Redbook and don't even come on disc anymore, so MS doesn't care.

Lately I've discovered this fork of ogg-winmm (https://github.com/ayuanx/ogg-winmm) which works very well with the games I've tested it on and lets you set the volume via ini file.

As a workaround that seems to be very promising, I will look into this, thanks

Out of interest, what would need to be done to restore that link in modern Windows? is there any software at all that exists that does this?

There is audio data going from somewhere to somewhere, if found it could be intercepted. I wish I was a software developer for things like this

CD volume control from games doesn't work even in XP for me. 2008 motherboard, SATA controller in AHCI mode.

If you want working volume control, DXWnd is the best solution IMO. It lets you play music from CD or from ripped audio files.