What's the purpose of people shouting "Hello" into the phone several times after they've clearly been disconnected?

Question

This is usually done with a landline phone. The character calls someone or someone is calling him, they talk for a while and then for any reason the other person hangs up earlier than the character thinks they should do so.At this moment the character hears continuous tone from the handset (we know this because we hear it too) which means that the conversation is over, deal with it. He should have heard the tone, optionally curse and then either hang up or call that person back/again or perhaps just move on.Yet the character will keep saying or better yet shouting "Hello???" into the handset several times before he finally understands that. What's the purpose of this? How does it make any sense?

Answer 1

The person realizes the man on the phone disconnected, but he is in denial because maybe he had something important to say or it was something urgent.