CD audio tested and confirmed working with "Neko Project 21/W x64 ver.0.86 rev.94"
I use the latest one found here:
https://simk98.github.io/np21w/download.html

Under "Harddisk" tab, do the following:
Insert "Appareden - The Sacrosanct Dragon (Japan) [T-En by 46 OkuMen v0.9.9.2] [CD version] [n].hdi" in IDE#0
Insert "Appareden - The Sacrosanct Dragon (Japan) [CDDA] [n].cue" in IDE#2
Make sure "Appareden - The Sacrosanct Dragon (Japan) [CDDA] [n].bin" is alongside the cue (obviously :p)

Reset emulation and reload game, select CD when "Select a sound source" menu appears.
Profit.

The NeoKobe image has a misconfigured config.sys file.
I corrected this so CD audio will play.

This had to be changed:
DEVICEHIGH=A:\TOOLS\NECCDD.SYS /D:CD_101 -> DEVICEHIGH=A:\TOOLS\NECCDM.SYS /D:CD_101