Manual Evaluation of synthesised Sign Language Avatars

The evaluation discussed in this paper explores the role that underlying facial expressions might have regarding understandability in sign language avatars. Focusing specifically on Irish Sign Language (ISL), we examine the Deaf community’s appetite for sign language avatars. The work presented explores the following hypothesis: Augmenting an existing avatar with various combinations of the 7 widely accepted universal emotions identified by Ekman [1] to achieve underlying facial expressions, will make that avatar more human-like and consequently improve usability and understandability for the ISL user. Using human evaluation methods [2] we compare an augmented set of avatar utterances against a baseline set, focusing on two key areas: comprehension and naturalness of facial configuration. We outline our approach to the evaluation including our choice of ISL participants, interview environment, and evaluation methodology

Methodology for developing a Speech into Sign Language Translation System in a New Semantic Domain

This paper proposes a methodology for developing a speech into sign language translation system considering a user-centered strategy. This method-ology consists of four main steps: analysis of technical and user requirements, data collection, technology adaptation to the new domain, and finally, evalua-tion of the system. The two most demanding tasks are the sign generation and the translation rules generation. Many other aspects can be updated automatical-ly from a parallel corpus that includes sentences (in Spanish and LSE: Lengua de Signos Española) related to the application domain. In this paper, we explain how to apply this methodology in order to develop two translation systems in two specific domains: bus transport information and hotel reception

Emotional Facial Expressions in Synthesised Sign Language Avatars: A Manual Evaluation

This research explores and evaluates the contribution that facial expressions might have regarding improved comprehension and acceptability in sign language avatars. Focusing specifically on Irish Sign Language (ISL), we examine the Deaf 1 community’s responsiveness to sign language avatars. The hypothesis of this is: Augmenting an existing avatar with the 7 widely accepted universal emotions identified by Ekman [1] to achieve underlying facial expressions, will make that avatar more human-like and improve usability and understandability for the ISL user. Using human evaluation methods [2] we compare an augmented set of avatar utterances against a baseline set, focusing on 2 key areas: comprehension and naturalness of facial configuration. We outline our approach to the evaluation including our choice of ISL participants, interview environment and evaluation methodology. The evaluation results reveal that in a comprehension test there was little difference between the baseline avatars and those augmented with emotional facial expression also we found that the avatars are lacking various linguistic attributes

Emotional Facial Expressions in Synthesised Sign Language Avatars: a Manual Evaluation.

This research explores and evaluates the contribution that facial expressions might have regarding improved comprehension and acceptability in sign language avatars. Focusing specifically on Irish sign language (ISL), the Deaf (the uppercase ‘‘D’’ in the word ‘‘Deaf’’ indicates Deaf as a culture as opposed to ‘‘deaf’’ as a medical condition) community’s responsiveness to sign language avatars is examined. The hypothesis of this is as follows: augmenting an existing avatar with the seven widely accepted universal emotions identified by Ekman (Basic emotions: handbook of cognition and emotion. Wiley, London, 2005) to achieve underlying facial expressions will make that avatar more human-like and improve usability and understandability for the ISL user. Using human evaluation methods (Huenerfauth et al. in Trans Access Comput (ACM) 1:1, 2008), an augmented set of avatar utterances is compared against a baseline set, focusing on two key areas: comprehension and naturalness of facial configuration. The approach to the evaluation including the choice of ISL participants, interview environment, and evaluation methodology is then outlined. The evaluation results reveal that in a comprehension test there was little difference between the baseline avatars and those augmented with emotional facial expression. It was also found that the avatars are lacking various linguistic attributes

The Role of Emotional and Facial Expression in Synthesised Sign Language Avatars

This thesis explores the role that underlying emotional facial expressions might have in regards to understandability in sign language avatars. Focusing specifically on Irish Sign Language (ISL), we examine the Deaf community’s requirement for a visual-gestural language as well as some linguistic attributes of ISL which we consider fundamental to this research. Unlike spoken language, visual-gestural languages such as ISL have no standard written representation. Given this, we compare current methods of written representation for signed languages as we consider: which, if any, is the most suitable transcription method for the medical receptionist dialogue corpus. A growing body of work is emerging from the field of sign language avatar synthesis. These works are now at a point where they can benefit greatly from introducing methods currently used in the field of humanoid animation and, more specifically, the application of morphs to represent facial expression. The hypothesis underpinning this research is: augmenting an existing avatar (eSIGN) with various combinations of the 7 widely accepted universal emotions identified by Ekman (1999) to deliver underlying facial expressions, will make that avatar more human-like. This research accepts as true that this is a factor in improving usability and understandability for ISL users. Using human evaluation methods (Huenerfauth, et al., 2008) the research compares an augmented set of avatar utterances against a baseline set with regards to 2 key areas: comprehension and naturalness of facial configuration. We outline our approach to the evaluation including our choice of ISL participants, interview environment, and evaluation methodology. Remarkably, the results of this manual evaluation show that there was very little difference between the comprehension scores of the baseline avatars and those augmented withEFEs. However, after comparing the comprehension results for the synthetic human avatar “Anna” against the caricature type avatar “Luna”, the synthetic human avatar Anna was the clear winner. The qualitative feedback allowed us an insight into why comprehension scores were not higher in each avatar and we feel that this feedback will be invaluable to the research community in the future development of sign language avatars. Other questions asked in the evaluation focused on sign language avatar technology in a more general manner. Significantly, participant feedback in regard to these questions indicates a rise in the level of literacy amongst Deaf adults as a result of mobile technology

TR-2015001: A Survey and Critique of Facial Expression Synthesis in Sign Language Animation

Sign language animations can lead to better accessibility of information and services for people who are deaf and have low literacy skills in spoken/written languages. Due to the distinct word-order, syntax, and lexicon of the sign language from the spoken/written language, many deaf people find it difficult to comprehend the text on a computer screen or captions on a television. Animated characters performing sign language in a comprehensible way could make this information accessible. Facial expressions and other non-manual components play an important role in the naturalness and understandability of these animations. Their coordination to the manual signs is crucial for the interpretation of the signed message. Software to advance the support of facial expressions in generation of sign language animation could make this technology more acceptable for deaf people. In this survey, we discuss the challenges in facial expression synthesis and we compare and critique the state of the art projects on generating facial expressions in sign language animations. Beginning with an overview of facial expressions linguistics, sign language animation technologies, and some background on animating facial expressions, a discussion of the search strategy and criteria used to select the five projects that are the primary focus of this survey follows. This survey continues on to introduce the work from the five projects under consideration. Their contributions are compared in terms of support for specific sign language, categories of facial expressions investigated, focus range in the animation generation, use of annotated corpora, input data or hypothesis for their approach, and other factors. Strengths and drawbacks of individual projects are identified in the perspectives above. This survey concludes with our current research focus in this area and future prospects

Data-driven Synthesis of Animations of Spatially Inflected American Sign Language Verbs Using Human Data

Techniques for producing realistic and understandable animations of American Sign Language (ASL) have accessibility benefits for signers with lower levels of written language literacy. Previous research in sign language animation didn’t address the specific linguistic issue of space use and verb inflection, due to a lack of sufficiently detailed and linguistically annotated ASL corpora, which is necessary for modern data-driven approaches. In this dissertation, a high-quality ASL motion capture corpus with ASL-specific linguistic structures is collected, annotated, and evaluated using carefully designed protocols and well-calibrated motion capture equipment. In addition, ASL animations are modeled, synthesized, and evaluated based on samples of ASL signs collected from native-signer animators or from signers recorded using motion capture equipment. Part I of this dissertation focuses on how an ASL corpus is collected, including unscripted ASL passages and ASL inflecting verbs, signs in which the location and orientation of the hands is influenced by the arrangement of locations in 3D space that represent entities under discussion. Native signers are recorded in a studio with motion capture equipment: cyber-gloves, body suit, head tracker, hand tracker, and eye tracker. Part II describes how ASL animation is synthesized using our corpus of ASL inflecting verbs. Specifically, mathematical models of hand movement are trained on animation data of signs produced by a native signer. This dissertation work demonstrates that mathematical models can be trained and built using movement data collected from humans. The evaluation studies with deaf native signer participants show that the verb animations synthesized from our models have similar understandability in subjective-rating and comprehension-question scores to animations produced by a human animator, or to animations driven by a human’s motion capture data. The modeling techniques in this dissertation are applicable to other types of ASL signs and to other sign languages used internationally. These models’ parameterization of sign animations can increase the repertoire of generation systems and can automate the work of humans using sign language scripting systems

Data-Driven Synthesis and Evaluation of Syntactic Facial Expressions in American Sign Language Animation

Technology to automatically synthesize linguistically accurate and natural-looking animations of American Sign Language (ASL) would make it easier to add ASL content to websites and media, thereby increasing information accessibility for many people who are deaf and have low English literacy skills. State-of-art sign language animation tools focus mostly on accuracy of manual signs rather than on the facial expressions. We are investigating the synthesis of syntactic ASL facial expressions, which are grammatically required and essential to the meaning of sentences. In this thesis, we propose to: (1) explore the methodological aspects of evaluating sign language animations with facial expressions, and (2) examine data-driven modeling of facial expressions from multiple recordings of ASL signers. In Part I of this thesis, we propose to conduct rigorous methodological research on how experiment design affects study outcomes when evaluating sign language animations with facial expressions. Our research questions involve: (i) stimuli design, (ii) effect of videos as upper baseline and for presenting comprehension questions, and (iii) eye-tracking as an alternative to recording question-responses from participants. In Part II of this thesis, we propose to use generative models to automatically uncover the underlying trace of ASL syntactic facial expressions from multiple recordings of ASL signers, and apply these facial expressions to manual signs in novel animated sentences. We hypothesize that an annotated sign language corpus, including both the manual and non-manual signs, can be used to model and generate linguistically meaningful facial expressions, if it is combined with facial feature extraction techniques, statistical machine learning, and an animation platform with detailed facial parameterization. To further improve sign language animation technology, we will assess the quality of the animation generated by our approach with ASL signers through the rigorous evaluation methodologies described in Part I