Speech impairment - moderate . Speech impairment - severe . A telephone with a sensitive microphone will help persons with quiet voices or with restricted neck and chest movement that makes speaking difficult. It is also important for the user to be able to adjust the sensitivity of the microphone so that it can be used by either a person with a weak voice or a normal voice. Amplification of the microphone should be user controlled and should reset on call termination.
Telephone features that make a difference .