A great help at home, office, factory, hospital, school, nursing home, church, retreat, camp, meeting, restaurant, party, ballgame, any place or event - one to one conversation or group activity - and in a car, bus, plane or train to get above engine and road noises.
HOW TO PREDICT WHETHER AMPLIFICATION IS LIKELY TO BE SUCCESSFUL?
Choose a quiet room and a listener with average hearing.
Position the listener so that the speaker's mouth is about 12" from the listener's ears. (Listener should close eyes to avoid lip reading.)
If the listener can understand about half of what the speaker says, then there is probably enough voice to make good use of an amplifier. If some sound can be heard, though not loud enough to be understandable, then it is still possible that a larger amp and sensitive mic might bring the voice up to a usable level.
IMPORTANT: An amplifier user must be able to shape words fairly well - amplifiers improve only volume, not articulation - though freedom from worry about volume may allow more concentration on articulation and consistency of voice production.