A framework is proposed to account for the generic design factors which interact to determine output rate in the use of communication aids for patients with neuromotor speech deficit. These factors, C (cost in language units per word), L (code length in motor acts per unit) and T (time per motor act) are in a trade-off relationship so that an increment or decrement in any one is not sufficient to determine the overall effect on rate of communication. Data is presented from 2 studies to illustrate ways in which this interaction may operate. Implications are drawn for nonvocal communication device design.
Get full access to this article
View all access options for this article.
References
1.
CrochetiereW. J.An Anticipatory Display for Communication by the Severely Disabled Nonvocal Person. Society for Information Display Digest, 1977, 150–151.
2.
FouldsR.A.BaletsaB.CrochetiereW. J.MeyerC.The Tufts Non-Vocal Communication Program. Proceedings of the 1976 Conference on Systems and Devices for the Disabled, 14–17.
3.
Goodenough-TrepagnierC.PratherP.Communication Systems for the Nonvocal Based on Frequent Phoneme Sequences, Journal of Speech and Hearing Research, 1981, 24, 322–329.
4.
Goodenough-TrepagnierC.TarryE.PratherP.Derivation of an Efficient Nonvocal Communication System. Human Factors, 1982, 24(2), 163–172.
5.
HowesD.Vocabulary Size Estimated from the Distribution of Word Frequencies, in MyklebustH. (Ed.). Progress in Learning Disabilities, Gruhn & Stratton, 1971,.
