Upgrading to Ubuntu 16.04 LTS resulted in distorted sound when connecting my laptop to a TV and trying to play sound through the HDMI TV connection. The fix was to change the default.pa PulseAudio config file as follows:

1. Open the config file using sudo gedit /etc/pulse/default.pa
2. Change the line load-module module-udev-detect to  load-module module-udev-detect tsched=0. This disables tsched which enables the interrupt based timing on your sound card.

That’s it!