[Jon Edwards]"I would like to know if it's possible to add an echo effect to a piece of audio so when it finishes, the last second or two echos out. If so, may I please know how this is done?"
Add it to the Track instead of the Event. You have obviously figured out that the audio ends when the event ends so effects like delay and reverb get cut off. You must add them to the Track so that they continue to play after the initial audio has stopped.