It doesn't work and doesn't appear on dmesg until the module is manually inserted with

modprobe snd-azt2320

ISA cards are apparently not modprobed automatically at bootup so you'll have to use hwinfo or a similar tool to find it out (Driver Activation Cmd:). They also lack a vendor ID so add the PCI Vendor from the PCI ID Database https://pci-ids.ucw.cz/read/PC/ and pass it in the Product ID field to be able to insert, in this case Aztech is 11ae. CS4231 is the chip found by alsamixer. Product year is either 1997 or 1998.

hwinfo --verbose --sound

23: ISA(PnP) 01.0: 0401 Multimedia audio controller             
  [Created at isapnp.142]
  Unique ID: R_Yp.JCbCnR0V0XF
  SysFS ID: /devices/pnp1/01:01/01:01.00
  SysFS BusID: 01:01.00
  Hardware Class: sound
  Model: "Aztech AZT1008 PnP SOUND DEVICE"
  Vendor: AZT "Aztech Systems"
  Device: eisa 0x1008 "AZT1008 PnP SOUND DEVICE"
  SubVendor: AZT "Aztech Systems"
  SubDevice: eisa 0x0500 
  Driver Info #0:
    Driver Status: snd-azt2320 is active
    Driver Activation Cmd: "modprobe snd-azt2320"
  Config Status: cfg=new, avail=yes, need=no, active=unknown

dmesg

[  153.033421] azt2320 01:01.01: [io  0x0220-0x022f]
[  153.033449] azt2320 01:01.01: [io  0x0388-0x038f]
[  153.033473] azt2320 01:01.01: [io  0x0534-0x0537]
[  153.033593] azt2320 01:01.01: [irq 5]
[  153.033613] azt2320 01:01.01: [dma 1]
[  153.033628] azt2320 01:01.01: [dma 3]
[  153.036007] azt2320 01:01.01: activated
[  153.036041] azt2320 01:01.02: [io  0x0330-0x0331]
[  153.036088] azt2320 01:01.02: [io  0x0300-0x0301]
[  153.036207] azt2320 01:01.02: [irq 10]
[  153.040217] azt2320 01:01.02: activated
[  153.054222] SA sound/isa/wss/wss_lib.c:447 mce_down - exit = 0xb
[  153.064207] SA sound/isa/wss/wss_lib.c:447 mce_down - exit = 0xb
[  153.074207] SA sound/isa/wss/wss_lib.c:447 mce_down - exit = 0xb
[  153.084204] SA sound/isa/wss/wss_lib.c:447 mce_down - exit = 0xb
[  153.094209] SA sound/isa/wss/wss_lib.c:447 mce_down - exit = 0xb