Having just read an insightfulblog post on the behaviour of children with cochlea implants I am reminded of the immense difficulties in communication that arises at the other end of developmental spectrum - acquired hearing loss in later life of old age.
I recall vividly as a young care assistant in a foreign country (UK) asking an elderly resident if they would like butter on their toast. "What?" came the very load response. Over enunciating in my very clearest diction (which is quite clear having had extensive elocution training for singing as a child) I repeated the phrase several times ever loader, ever clearer. With the other local carers by then starring at me I stood back, evaluated and said "Want some bu'er" and not all that loudly. "Oh, yes thanks, love" came the reply.
We forget how important consistency of phonetic sounds becomes with hearing loss. My accent, even when pushed to very clear received pronunciation was not anything like the sounds this person was used to hearing. Combine that with hearing loss and you have real trouble. Initially I thought they may have been taking the mickey, treating me with contempt regarding my colonial roots. No, it became clear as I strengthened my local dialect that communication with this elderly group of people for whom I had become a critical companion improved with every clipped 't' and local colloquialism I acquired.
Excellence in communication is about recognising the needs of the person to whom you are directing the communication. Very tricky to teach toddlers I grant you. Care assistants, nurses, teachers and parents however need to understand this. It is certainly a good lesson to take into the work environment too even where hearing impairment may not be an issue. When communication is unclear to the person to whom it is directed we may not always see the behaviour we expect.