Towards the end of the story there will be a mission where you need to meet with someone who will offer you a way to relax yourself through recording sounds of the city.
You need to travel to each of the icons to activate the sound you're looking for (Hell's Kitchen doesn't have a sound to look for).
Some of these are easy, some may take a little extra effort; the first sound is almost given to you so the list doesn't include it.
I've included both the general area if you want to look for yourself (the yellow area on the map you're given is extremely vague and didn't help me at all) and a spoiler for the exact thing you're supposed to scan.
HarlemLook for a couple of basketball courts and head onto the main road to the right of them.
Upper West SideLook around the fire hall
Central ParkJump off the bridge and head stealthily towards the gazebo
Upper East SideJump to the other side of the street from the hologram and look around the roof of the school
MidtownAfter activating the hologram jump down to the main road and start scanning around
*** Spoiler - click to reveal ***The recruiting booth in front of the movie ad that says "Me, You, and the Dog" (you may need to stand in the area with the people sitting at the patio tables)
GreenwichRight after activating the hologram just throw on your scanner, you're close enough already
ChinatownHead to the top left corner of the yellow square and look around
Financial DistrictStay on the big circle structure and you'll get it eventually
If the trophy doesn't pop go into the Collections tab and make sure there are 10 sounds; you may need to play the final mix