Final answer:
Compression is the recording trick used to enhance and fortify the vocal.
Step-by-step explanation:
The recording trick used to enhance and fortify the vocal is Compression. Compression is a technique used in audio production to control the dynamic range of a vocal track. It evens out the levels of the vocal, making it sound more consistent and present in the mix.
While Auto-Tune is a popular vocal effect that corrects pitch, and Reverb and Delay are effects that add space and depth to the vocal, Compression is the recording trick specifically used to enhance and fortify the vocal.