Speech-generating devices (SGDs), also known as voice output communication aids, are electronic augmentative and alternative communication (AAC) systems used to supplement or replace speech or writing for individuals with severe speech impairments, enabling them to verbally communicate. SGDs are important for people who have limited means of interacting verbally, as they allow individuals to become active participants in communication interactions. They are particularly helpful for patients with amyotrophic lateral sclerosis (ALS) but recently have been used for children with predicted speech deficiencies. There are several input and display methods for users of varying abilities to make use of SGDs. Some SGDs have multiple pages of symbols to accommodate a large number of utterances, and thus only a portion of the symbols available are visible at any one time, with the communicator navigating the various pages. Speech-generating devices can produce electronic voice output by using digitized recordings of natural speech or through speech synthesis—which may carry less emotional information but can permit the user to speak novel messages. The content, organization, and updating of the vocabulary on an SGD is influenced by a number of factors, such as the user's needs and the contexts that the device will be used in. The development of techniques to improve the available vocabulary and rate of speech production is an active research area. Vocabulary items should be of high interest to the user, be frequently applicable, have a range of meanings, and be pragmatic in functionality. There are multiple methods of accessing messages on devices: directly or indirectly, or using specialized access devices—although the specific access method will depend on the skills and abilities of the user. SGD output is typically much slower than speech, although rate enhancement strategies can increase the user's rate of output, resulting in enhanced efficiency of communication. The first known SGD was prototyped in the mid-1970s, and rapid progress in hardware and software development has meant that SGD capabilities can now be integrated into devices like smartphones. Notable users of SGDs include Stephen Hawking, Roger Ebert, Tony Proudfoot, and Pete Frates (founder of the ALS Ice Bucket Challenge). Speech-generating systems may be dedicated devices developed solely for AAC, or non-dedicated devices such as computers running additional software to allow them to function as AAC devices. (en)
Luo, F., Higginbotham, D. J., & Lesher, G. . Webcrawler: Enhanced augmentative communication. Paper presented at CSUN Conference on Disability Technology, March, Los Angeles. (en)
Johansen, A. S., Hansen, J. P., Hansen, D. W., Itoh, K., and Mashino, S. 2003. Language technology in a predictive, restricted on-screen keyboard with dynamic layout for severely disabled people. In Proceedings of the 2003 EACL Workshop on Language Modeling for Text Entry Methods . Association for Computational Linguistics, Stroudsburg, PA, USA, 59–66. (en)
Black, R., Reddington, J., Reiter, E., Tintarev, N., and Waller A.. 2010. Using NLG and sensors to support personal narrative for children with complex communication needs. In Proceedings of the NAACL HLT 2010 Workshop on Speech and Language Processing for Assistive Technologies . Association for Computational Linguistics, Stroudsburg, PA, USA, 1–9. (en)
Blischak, D. M., Lombardino, L. J., & Dyson, A. T. . Use of speech-generating devices: In support of natural speech. Augmentative and Alternative Communication, 19 (en)
Dominowska, E., Roy, D., & Patel, R. . An adaptive context-sensitive communication aid. Proceedings of the CSUN International Conference on Technology and Persons with Disabilities, Northridge, CA. (en)
Friedman, M. B., G. Kiliany, M. Dzmura, D. Anderson. "The Eyetracker Communication System," Johns Hopkins APL Technical Digest, vol. 3, no. 3, 1982. 250–252 (en)
Dempster, M., Alm, N., and Reiter, E.. 2010. Automatic generation of conversational utterances and narrative for augmentative and alternative communication: a prototype system. In Proceedings of the NAACL HLT 2010 Workshop on Speech and Language Processing for Assistive Technologies . Association for Computational Linguistics, Stroudsburg, PA, USA, 10–18. (en)
Venkatagiri, H. S. 1995. Techniques for enhancing communication productivity in AAC: A review of research. American Journal of Speech-Language Pathology 4, 36–45. (en)
Roark, B., de Villiers, J., Gibbons, C., and Fried-Oken, M.. 2010. Scanning methods and language modeling for binary switch typing. In Proceedings of the NAACL HLT 2010 Workshop on Speech and Language Processing for Assistive Technologies . Association for Computational Linguistics, Stroudsburg, PA, USA, 28–36. (en)
Glennen, Sharon L. and Decoste, Denise C. . The Handbook of Augmentative and Alternative Communication. Singular Publishing Group, Inc.: San Diego, CA. (en)
Reddington, J., & Coles-Kemp, L. . Trap Hunting: Finding Personal Data Management Issues in Next Generation AAC Devices. In Proceedings of the Second Workshop on Speech and Language Processing for Assistive Technologies . Edinburgh, Scotland, UK: Association for Computational Linguistics. (en)
Friedman, M.B., Kiliany, G. and Dzmura, M. An Eye Gaze Controlled Keyboard. Proceedings of the 2nd International Conference on Rehabilitation Engineering, 446–447 (en)
R. Patel and R. Radhakrishnan. 2007. Enhancing Access to Situational Vocabulary by Leveraging Geographic Context. Assistive Technology Outcomes and Benefits (en)
