Loud noise from truck selling water in Narimedu

There’s this mini truck that sells water and they come right around late afternoon, honking the horn EXTREMELY LOUD!! I’ve already requested him multiple times to not honk the horn in front of my house but now, he’s started to honk it extra loud and long right in front of my house. My baby takes his nap right around this time and my father who is a cardiac patient gets startled. I’m hella sure his horn is louder than it should be and it violates traffic rules. How can I go about this?