No HDMI sound on GeForce GTX 950

I am running Ubuntu 22.04 with Nvidia graphic card :

NVIDIA Corporation GM206 [GeForce GTX 950] (rev a1)

and Nvidia driver v525.60.11.

The video output is perfect.

I tested the HDMI sound for the first time some days ago, and I have none; the sound on my screen is at 100%.
On the line output and on two USB headsets, the sound is normal.

Can somebody help me ?

R. Grasso

My bad ! The screen is old, and does not have speakers ! It only has a jack outlet, and if I plug a headset on this outlet, the sound is perfect !

Case closed.