A central sound system, an educational device to aid teachers and administrators.

Nangle, Katherine Louise2014-12-152014-12-1519471947b14689649https://archive.org/details/centralsoundsyst00nanghttps://hdl.handle.net/2144/10079Thesis (M.A.)--Boston University This item was digitized by the Internet Archive.en-USBased on investigation of the BU Libraries' staff, this work is free of known copyright restrictions.A central sound system, an educational device to aid teachers and administrators.Thesis/Dissertation