Audio Precision has added a new speech intelligibility measurement option for APx500 audio test software based upon the ABC-MRT speech processing algorithm. Measuring speech intelligibility is an important capability for engineers designing and validating a wide range of communication systems, products and components. One of the more precise definitions of intelligibility is the proportion of speech items (words and/or speech sounds) uttered by a talker, and sent via a communication system, that can be recognized by the listener.
Introduction to ABC-MRT
ABC-MRT, or Articulation-Band Correlation Modified Rhyme Test, was developed by the Institute for Telecommunication Sciences (ITS) of the United States National Telecommunications and Information Administration (NTIA). It follows the paradigm of the Modified Rhyme Test, a technique for assessing speech intelligibility that involves subjective assessment by human subjects as detailed in ANSI/ASA Standard S3.2. To eliminate the time, complexity, and expense of the traditional human subject-based methodology, ABC-MRT uses a form of automatic speech recognition (ASR) to conduct an automated measurement that is closely correlated—greater than 95%—to a Modified Rhyme Test. An added benefit of ABC-MRT is its use of real speech (English only), allowing it to support the testing of systems that use noise suppression and/or codecs that only pass speech.
Integrated Audio, Electro-Acoustic and Intelligibility Measurement
Using the ABC-MRT option allows developers to measure the speech intelligibility of their designs with AP’s industry-leading instrumentation and use that same equipment for the rest of their audio and electro-acoustic test requirements. Once installed, the ABC-MRT measurement can be easily incorporated into any test sequence.
The ABC-MRT software option (APX-SW-ABC-MRT) is available now and retails for $2,100. It requires APx500 audio measurement software release v4.5.2 (or later) and is compatible with all analyzers in the APx500 Series. For more information, visit Audio Precision.