scope:

Scope and limitations

The scope of this standard includes the measurement of the intelligibility of speech over entire communication systems and the evaluation of the contributions of elements of speech communication systems. The scope also includes evaluation of the factors that affect the intelligibility of speech.

In this standard the intelligibility of speech over a speech communication system is measured by comparing the monosyllabic words trained listeners receive and identify with the words trained talkers or speech coders speak into a communication system that connects the talkers (or speech coders) with the listeners. The standard requires the intelligibility measurements to be made with talkers and listeners who are native speakers of English and who have no speech or hearing defects.

Limitations.

This standard specifies what should be measured and reported to assess a communication system, but it does not specify the test conditions. This limitation prohibits comparisons between evaluations done under different test conditions.

This standard is not intended for use in evaluating automatic speech recognition devices; the sets of speech materials specified in this standard have not been shown to be appropriate or valid for testing systems that include such devices.

This standard is not intended for use in evaluating the intelligibility of text-to-speech systems; the sets of speech materials specified in this standard have not been shown to be appropriate or valid for testing such systems.

This standard is not intended for use in evaluating the articulatory abilities of talkers with speech disorders or for use in evaluating the speech discrimination abilities of listeners with hearing deficiencies.

This standard is not intended for use in evaluating listeners' abilities to identify talkers or their emotional state. Neither is the standard intended for use in evaluating the overall quality of a speech communication system.