being quietly spoken wouldn’t seem to be a disability.
You would, I think, need to get a better description and reasoning for the problem.
Just as important is which descriptors are being applied?
What aid or appliance is envisaged? Or is it communication support?
From the attached decision at para 21
I accept that anxiety caused by mental health difficulties can potentially lead to the scoring of points under activity 7 such that the activity and its associated descriptors are not simply concerned with physical or sensory impairments to communication. ... If a claimant has difficulty in speaking as a result of anxiety, or perhaps some other mental health problem, it must be asked what it is that causes that difficulty. Is it a fear of social engagement? Or is it something simply connected to the activity of communicating verbally? It could, of course, be both but, equally, it could be one or the other. So, it seems to me an anxious claimant who, for example, is not able to communicate with strangers or persons who are not well known to him or is not able to do so when in the company of a large number of people but is able to verbally express himself or herself and understand communication with a person with whom they are familiar and comfortable would, in all probability, score points under activity 9 but not under activity 7. ...