Positives and negatives about interpreters for hard of hearing individuals?

If communication is done by visible means, then the easiest is to produce a written text that the other person can read - the difficulty is doing it fast enough (means using a computer, which makes errors) and the speed someone can read. If done by mouthing the words then the words need to be clear and spoken more slowly, and the difficulty is that many words are only slightly different mouth forms so it can be tricky to distinguish them (eg p from b, etc), if the communication is done by sign language again there are limitations but by visuallising total words some of the problems with similar sounds can be avoided but there can be a loss of subtlety. If the solution is to simply amplify the sound with a hearing aid then the difficulty is that all sounds tend to amplified and the brain has more trouble selecting out the words it wants to hear - a particular problem if in fact the hearing loss is only across a specific frequency range, although in this case a correctly configured hearing aid can help.