There are numerous healing frequencies on the radio depending on what difficulty you're on and they can be accessed once you reclaim your gear on Virtuous Mission. You only have to tune in to all the frequencies on your specific difficulty to earn this trophy, so there's no need to play through multiple times unless you're a glutton for punishment ... er, replaying.
I'm not certain where the frequencies can be found; in all honesty, I found this list on playstationtrophies.org, and can confirm the Very Easy frequencies are correct.
Very Easy / Easy
140.01
140.52
141.24
142.94
144.06
147.08
147.59
149.53
Normal
148.39
146.65
148.96
144.86
143.32
145.83
142.09
141.85
Hard
147.96
141.59
143.83
144.25
143.97
146.07
145.72
Extreme
146.45
148.66
140.16
148.78
142.42
141.42
145.18
149.39