PubMed Health⌕ Search

PubMed · 7647389

Developing AAC technologies: a personal story and philosophy.

Abstract

Research into and development of augmentative and alternative communication (AAC) technologies is an exciting but complex field. The development of a technologically based system which will be an alternative to, or will augment, the speech modality for the interpersonal communication needs of people with communication dysfunction is not an easy task. This is only a young field and thus much of the research methodology is not yet well defined. It is also a growing field, and one to which we would wish to attract new practitioners, and provide appropriate guidance to them. In any technological development project, it is important to define clearly a number of parameters of the project. These are: the client group; the knowledge base needed to solve the problems; the potential technologies that will help and their characteristics; and the time scales envisaged for completion of the research. The authors have been part of a research team working in this field for many years, and, in this paper, they will examine three research strategies which they have found particularly beneficial, illustrating the concepts discussed mainly by reference to personal experiences. The paper concentrates on a relatively narrow definition of technology-that which is often referred to as 'high technology' or information technology. This is not to deny, in any way, the importance to the AAC field of solutions based on other technology, and the authors would hope that some of the comments in the paper are also appropriate to researchers who are working with systems and techniques which do not depend on these technologies.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

A F Newell, N Alm. 1994. Developing AAC technologies: a personal story and philosophy.. https://doi.org/10.3109/13682829409031291

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Source-filter comparison of measurements of fundamental frequency perturbation and amplitude perturbation for synthesized voice signals.

SUMMARY: An investigation of the effect of glottal source aperiodicities (jitter, shimmer, and aspiration noise) on the estimation of fundamental frequency (f0) perturbation and amplitude perturbation, of synthesized, glottal source and voiced speech waveforms, is considered. Firstly, 4, cycle-event f0 estimators are examined: (1) waveform matching of the low-pass filtered waveform, (2) positive peaks (PPs) from the speech waveform, (3) PPs from the low-pass filtered waveform, and (4) positive zero crossings from the low-pass filtered waveform. The analysis shows that f0 perturbation measures taken from the low-pass filtered waveform are affected by both amplitude perturbation and random glottal noise, whereas, f0 perturbation measures taken from the PPs of the original waveform are affected by noise but not by amplitude perturbation. It is shown for the low-pass filter methods that the effects of amplitude perturbation and noise lead to increased errors in the measurement of f0 perturbation for the synthesized speech waveforms when compared with the synthesized glottal waveforms. Shimmer of the synthesized speech waveform is approximately equal to shimmer of the synthesized glottal source. However, noise and jitter affect measures of amplitude perturbation. The estimation of f0 perturbation from the synthesized speech waveform is shown to be nonlinearly related to f0 perturbation estimation from the synthesized glottal waveform as a consequence of the filtering action of the vocal tract. Low-pass filtering the voiced speech waveform is shown to provide a partial solution to this problem.

Communication Devices for People with Disabilities↗

Issues in AAC research: how much do we really understand?

PURPOSE: The purpose of this introductory paper is to provide some overview of and background to the issues that were raised at the Augmentative and Alternative Research Seminar in conjunction with the First Regional AAC conference on 23 February 2004. A group of 45 AAC researchers and professionals convened for one day to discuss some basic research issues in AAC. This paper highlights themes and perspectives that emerged from the research seminar discussions. METHOD: Literature reviews and discussion are used to provide a historical perspective on some of the issues raised. Two focus areas were identified for the purpose of this introductory paper; firstly, terminological issues that arose and secondly common themes that emerged during the paper presentations, discussions and/or written papers. Terminological issues include a brief description of the field of AAC for the benefit of those readers who might not be familiar with the field, whereafter the discussion focuses on the use of the term "complex communication needs" as referring to individuals who use AAC, the differentiation between symbols, signs, symbols sets and systems as well as the terms verbal and nonverbal, pre-linguistic and non-symbolic. The common themes throughout the papers include a discussion on the importance of context in communication, the chicken and egg question (i.e., comprehension and production), issues on multimodality, descriptive strategies for understanding interaction, and the use of typical interaction as a framework for understanding AAC interaction. CONCLUSIONS: In reviewing some of the issues in the field it is apparent that the issues we face now and those faced in AAC during earlier years are similar, however the need for a stronger database is apparent as the approach towards evidence-based practice becomes more prominent. The move to understand the nature of complex relationships in interaction is highlighted, for example, the multiple associations between environment, comprehension as well as the use of multi-modal communication. Whilst it became evident that most of these issues need further research in relation to typical interactions, applications to the field of AAC are most challenging.

Communication Devices for People with Disabilities↗