iMac 18,2 Sound Issues

[kalpana]

Kernel: 5.16.10-151610-generic
Ubuntu 20.04 LTS
Computer: iMac 18,2

Hi, I just installed Ubuntu on my iMac and have been enjoying it so far. However, there seems to be no audio on the system.
lspci lists the audio device as "Intel Corporation 100 Series/c230 Series Chipset family HD Controller (rev 31)"

I tried various fixes but not seem to have worked and the dummy output remains.
Help would be much appreciated.

Thanks in advance