ARCON maintains a complete speech communications laboratory facility in Woburn, MA with over 1000 sq. ft. of office space and 1500 sq. ft. of laboratory space. The facility accommodates four sound chambers, an extensive computer network, a communicability test bed, a vocoder implementation host laboratory, multipurpose (experimental/recording/maintenance) workstations, and a break area for the experimental subjects. Software capabilities include extensive signal processing and analysis tools. An in-house library is supplemented with computer access to the WWW and several technical journal archives.
The largest chamber is 10 ft. by 20 ft. and is used primarily for subjective evaluation. This chamber is equipped with audio and data stations that allow up to 16 subjects to be tested simultaneously for the same or separate tasks. A second 12 ft. by 12 ft. double-walled chamber is primarily used for the simulation of military and commercial acoustic noise fields. The chamber is equipped for sound reproduction and is specifically designed to reproduce the high energy, low frequency signals characteristic of ground vehicles. A smaller "phone booth "chamber is used for hearing screens and the recording of speech material in quiet environments. The fourth chamber is specially designed for the reproduction of aircraft sound fields. All chambers are interconnected for both audio and data signals.
The communicability test bed takes advantage of the sound chambers to simulate voice networks with up to 6 nodes. Each of these nodes can be characterized by its own acoustic background and transducers. The test bed allows for a variety of voice coders, channel impairments, conference bridges, or signal impairments to be imposed between any of the nodes. All voice conversations and data signals can be recorded at any point within the network.
ARCON has established an in-house host lab facility with the capability of providing voice coder and signal processing for multiple computer platforms and operating systems. This facility has been used for the host lab function in several government and commercial standardization efforts. The computing platforms include both SUN and PC systems running under SUN OS, Unix, Linux, HPUX, MSDOS, Windows, and Windows NT operating systems. Numerous reference coders and calibration algorithms are available. A complete set of compilers allows for the implementation of candidate coder software.
This facility also enables ARCON to perform a large variety of subjective evaluations. To date, the facility has been used to evaluate the intelligibility, quality, speaker recognizability, and communicability of military and civilian voice communication equipment.
The facility's extensive computer hardware and software capabilities provide support for research efforts in speech science, voice communications, multi-media conferencing, and the development of new subjective test methodologies.