An approach to processing of acoustic signals acquired at a user’s device include one or both of acquisition of parallel signals from a set of closely spaced microphones, and use of a multi-tier computing approach in which some processing is performed at the user’s device and further processing is performed at one or more server computers in communication with the user’s device. The glass compositions can be processed using fusion forming processes and float forming processes and are ion exchangeable. The niobium suboxide powder is suitable for the production of: capacitors having an insulator layer of niobium pentoxide; capacitor anodes produced from the niobium suboxide powder; and corresponding capacitors. Due to this construction, minority carriers are removed also from the rear side of the channel. In addition, it is possible to fabricate the EL display device of the present invention with most of an existing manufacturing line for liquid crystal display devices.