Improving the intelligibility of dysarthric speech using a time domain pitch synchronous-based approach

Dysarthria is a motor speech impairment that reduces the intelligibility of speech. Observations indicate that for different types of dysarthria, the fundamental frequency, intensity, and speech rate of speech are distinct from those of unimpaired speakers. Therefore, the proposed enhancement technique modifies these parameters so that they fall in the range for unimpaired speakers. The fundamental frequency and speech rate of dysarthric speech are modified using the time domain pitch synchronous overlap and add (TD-PSOLA) algorithm. Then its intensity is modified using the fast Fourier transform (FFT) and inverse fast Fourier transform (IFFT)-based approach. This technique is applied to impaired speech samples of ten dysarthric speakers. After enhancement, the intelligibility of impaired and enhanced dysarthric speech is evaluated. The change in the intelligibility of impaired and enhanced dysarthric speech is evaluated using the rating scale and word count methods. The improvement in intelligibility is significant for speakers whose original intelligibility was poor. In contrast, the improvement in intelligibility was minimal for speakers whose intelligibility was already high. According to the rating scale method, for diverse speakers, the change in intelligibility ranges from 9% to 53%. Whereas, according to the word count method, this change in intelligibility ranges from 0% to 53%

The design and evaluation of novel technologies for the self monitoring and management of Parkinson's symptoms

PhD ThesisThis thesis explores how digital technologies might better support people with Parkinson’s (PwP) to take control of their condition, by engaging in self monitoring and management practices. The specific focus of this thesis is around issues managed by Speech and Language Therapists (SLTs) (namely drooling and speech and voice changes). Three case studies were used to explore the ways that different technologies might be configured to aid the self monitoring and management of these speech and drooling symptoms. The first case study describes an evaluation of PDCue, a wrist worn device to assist the self management of drooling through the use of a temporal cueing method, to increase swallowing frequency. This study showed evidence that drooling can be behaviourally self managed through cueing—like other symptoms of Parkinson’s such as gait freezing—and proved a viable first step towards re-considering the use of additional medications as a first option for drooling treatment. However, whilst this study proved successful in understanding the ways in which a simple, temporal cueing technique might support drooling management, it opened up questions around the ways in which PwP might use technology to actively think about and understand their condition through self monitoring, and use this information to support self management practices further. In response, the second case study describes the design and evaluation of LApp, an application to support both the self monitoring and management of vocal loudness issues through the use of an insitu cueing approach. The Google Glass was chosen as the platform to run the cueing method on, due to its technical capabilities as a multi-sensor, wearable platform, to analyse a constant stream of audio and provide real time visual prompts to support the wearer in increasing their volume at times when it is needed in conversation. This study highlighted how participants saw value in LApp in supporting their loudness issues, but also noted a desire for participants to understand more about their speech and the SLT strategies that they were required to do in order to improve it. The third case study drew upon this desire for increased understanding by developing and evaluating Speeching, which employed crowdsourcing through a smartphone application to support the self monitoring of speech and voice changes, through the provision of human feedback, and the subsequent effect that this feedback had on self management practices. This study yielded positive responses from participants, who valued the anonymous feedback from the crowd and the support that this provided them in configuring their home based speech practice. A final discussion chapter draws the 3 case studies together and discusses the lessons learned throughout the research. It discusses the overall research questions for the thesis in detail and describes the implications of the research for the wider HCI and medical communities. A framework is presented which aims to visualise the levels of agency that the studied technologies afforded and the levels of responsiveness required by participants to make sense of, and implement the information being provided by the devices in order to facilitate a change to the self monitoring and management practices. Through the design and evaluation of the described technologies and a synthesis of the findings across the span of the research, this thesis explores the ways in which PwP, with a diverse range of symptoms and related physical, social and emotional issues, might value digital technologies and their potential to facilitate new forms of self monitoring and self management in their everyday lives.The National Institute of Health Research (NIHR): The Engineering and Physical Sciences Research Council (EPSRC): Gordon Chapman Memorial Fund