My cousin always struggled at school. She was very physical and played ladies rugby but could not settle down to school work. She showed signs of bad behaviour too and all too often, others would lose their temper and shout.
A very English story... one day she was having a cup of tea with her mum. They were having a relaxed conversation and then my cousin asked, "What did you say?".
My aunt repeated her sentence, but still my cousin said she could not hear and that, she couldn't understand because the teacup was in front of her mum's mouths and therefore she couldn't hear what she was saying.
It turns out that at 11 years old, my cousin was lipreading most of the time. Later, she was diagnosed as hard of hearing and has worn a hearing aid ever since.
This shows the importance of early identification and recognition because by this point in her life, she had lost all confidence in her own ability and continued to not do well at school.