Where was the ban on the use of loudspeakers put forward?

Ministry of education and relevant departments. The Ministry of Education and relevant departments have not issued a document prohibiting teachers from using loudspeakers in class. In other words, it is not against the regulations for front-line teachers to use headphones in class. Whether sitting in class or taking classes through loudspeakers has nothing to do with teachers' morality.

1, amplifier generally refers to power amplifier. Power amplifier, referred to as power amplifier, generally refers to one of the most basic devices in audio system, commonly known as "amplifier". Its task is to amplify the weak electrical signal from the signal source (from the mixer in the professional audio system) to drive the speaker to make sound. It can also refer to other devices used for power amplification.