How deaf are you really?

Last night we decided to make the trip into the Waterfront in Cape Town to meet Doug for a meal. It is the holidays after all. On the way there Jethro fell into a deep sleep. I carried him to the meeting place and fell onto a nearby bench to wait for Doug to arrive. Two young adults were seated next to me. They were chatting between themselves and I was half resting Jethro,s head against my arm as it flopped down, drawn by gravity and half watching the people of the Cape as they went about Friday evening business. I guess the Waterfront is fairly noisy but I had not noticed this aspect of it before. I guess I am a little deaf in one ear. Anyway, the one young Adult turns to me and says these words..... " your phone is ringing" . ............. Really. she must be mistaken. Not my phone. I did not hear it - I did not hear it at all. Not a beep. I rummaged through my overflowing hand bag and found the said phone and .... yes 2 missed calls. Which begs the question. How deaf am I really?