White noise lines appear in class trials as Purple lines that usually block weak points. They are destroyed in a similar fashion to weak points. You scroll your retcile over it, but you press to destroy it. You can also touch the corresponding area on the rear touch pad. However, the second method is pretty confusing and it doesn't work all the time so it is recommended you use the first method.

For this trophy, you must destory a total of 500 white noise lines for it to unlock. Don't play class trials with the action difficulty set to Gentle. They don't appear at all in this difficulty. You need to play with the action difficulty set to at least Kind for them to appear.

If you play through the game spoiler free and destroy as many white noise lines as possible, this may come naturally. If it doesn't, then try the third trial on Mean. Keep playing the first Non-Stop Debate, just start shooting down the White Noise Lines over and over until the time reaches 1 minute, Then shoot the correct statement to continue. Repeat this process with all Non-Stop Debates in the trial until you get the trophy.