Subway train broadcast volume automatic adjustment method

The invention discloses a subway train broadcast volume automatic adjustment method, and belongs to the field of an embedded computer. The method is composed of a noise detection module and a volume adjustment module. A noise value of each guest room is detected in real time by the noise detection module through a plurality of noise detection devices installed in guest rooms; the noise values sent by the noise detection devices are received by a master controller through an MVB bus communication mechanism; finally, the noise values are stored in the master controller according to guest room numbers. All noise values of the guest rooms stored in the master controller are read by the volume adjustment module; broadcast volume values corresponding to the noise detection devices are obtained by calculating according to linear relation between noise of the guest rooms and broadcast volume of guest rooms; an average number of the broadcast volume values is obtained in the guest rooms at last, the average number is sent to trumpets of all the guest rooms. The broadcast volume can be adjusted automatically according to noise conditions of the guest rooms, and the device plays an important role in a subway passenger information system.