Voice amplifiers are used to amplify the sound of the speaker's voice in the hall, classroom or any other closed space. This one is for teachers who are not confident that the students are listening to them when they are speaking. Amplifiers are used in classrooms and other room spaces where students and teachers are working together and they need the sound to carry across the entire classroom. These speakers are used in classrooms, auditoriums, and other spaces where sound needs to be amplified. They cannot be used in outdoor spaces because the voice will be distorted and it will not be audible for everyone. Students may feel embarrassed by the fact that their teacher is wearing a speaker and this will also affect the teacher's authority if he uses the amplifier constantly in class.