In some cases, depending on the hardware used, the sound in EmulationStation may sound abnormal, like jerky. This short tutorial might help you if you are in the same case.
To do this, you need to connect via SSH and execute the following 2 lines:
mount -o remount,rw /
echo 'default-sample-rate = 48000' >> /etc/pulse/daemon.conf
Reboot and the sound should be correct.
You will need to do this again after each system update.