Shengli street, Xinglong town. Bayan County is a county in Harbin, Heilongjiang Province, a suburb of Harbin. It is located in the south-central part of Heilongjiang Province, in the hinterland of Songnen Plain. Teachers' loudspeakers can be used to amplify teachers' voices and facilitate teaching. Shengli Street in Xinglong Town sells it. It's called Wenxin Education Store, and it's affordable.