Play a spotify/youtube playlist of trigger noises (or record the noises in real life). Have it on very low volume so that you pup can hear it but is not reacting and is able to take treats. Give them treats/a chew while they listen. Repeat in multiple short (5-10 minute) sessions throughout the day. The next day, turn the volume up a click and repeat. Slowly, across multiple sessions, increase the volume of the sounds and keep rewarding your pup. If they stop being able to take treats at any point, turn the volume down again for a few more repeats. Eventually, they will not react even when the noise is loud.