This reply will be showed after approved! KenGoldenTree
If think he mentions that his ears were created to be the best, so I'm thinking he was tested on or operated on somehow to have extremely good hearing. May explain the barcode. Not sure if he's an android, but then again it's another world so anything is possible lol
http://www.mangago.zone/read-manga/sugar_my_baby/mrk/hs_v-1-chapter-3/pg-36/
looks like this one http://www.mangago.zone/read-manga/kimi_no_oto_ga_nari_yamanai/
Thank you!