Audacity has effects for adding echo and reverb. They both accomplish similar tasks but they are different effects. Echo basically creates a time-shifted duplicate of the original. So you hear a sound, then your hear that sound again slightly quieter while the original keeps playing. Reverb can create something like an echo but it is typically used to simulate speaking in a large room.
Audaicty's echo effect is quite simple. The "Delay Time (seconds)" is how long the echo waits before it starts. The "Decay Factor" is how long the echos take to fade away. Smaller values means less echo and bigger values mean more echo.
Delay. This is fancier echo effect with more customizeable settings
-Delay Type: regular
-Delay level: -6.0
-Delay time: 0.20
-Pitch change effect: Pitch/tempo
-Pitch change: 0.00
-Number of echos: 4
-Allow duration to change: Yes
GVerb is the effect that gives you the Reverberation. There is echo involved with reverb, but it's more complicated.
-Roomsize: 40
-Reverb time: 0.1
-Damping: 0.5
-Input bandwidth: 0.75
-Dry signal: -70
-Early Reflection level: 0
-Tail level: -17.5
When you are finished, unmute the original track and mess around with the gain for the reverb track until you get what you are looking for.
Echo manual.audacityteam.org/man/ec...
Delay manual.audacityteam.org/man/de...
GVerb presets wiki.audacityteam.org/wiki/GVe...
Reverb manual.audacityteam.org/man/re...