Effects of reinforcement on auditory stimulus control and threshold assessment with retarded children

Call number: LD2668 .T4 1969 L43Master of Scienc

DNN-Based Source Enhancement to Increase Objective Sound Quality Assessment Score

We propose a training method for deep neural network (DNN)-based source enhancement to increase objective sound quality assessment (OSQA) scores such as the perceptual evaluation of speech quality (PESQ). In many conventional studies, DNNs have been used as a mapping function to estimate time-frequency masks and trained to minimize an analytically tractable objective function such as the mean squared error (MSE). Since OSQA scores have been used widely for soundquality evaluation, constructing DNNs to increase OSQA scores would be better than using the minimum-MSE to create highquality output signals. However, since most OSQA scores are not analytically tractable, i.e., they are black boxes, the gradient of the objective function cannot be calculated by simply applying back-propagation. To calculate the gradient of the OSQA-based objective function, we formulated a DNN optimization scheme on the basis of black-box optimization, which is used for training a computer that plays a game. For a black-box-optimization scheme, we adopt the policy gradient method for calculating the gradient on the basis of a sampling algorithm. To simulate output signals using the sampling algorithm, DNNs are used to estimate the probability-density function of the output signals that maximize OSQA scores. The OSQA scores are calculated from the simulated output signals, and the DNNs are trained to increase the probability of generating the simulated output signals that achieve high OSQA scores. Through several experiments, we found that OSQA scores significantly increased by applying the proposed method, even though the MSE was not minimized

Low-Latency Sequence-to-Sequence Speech Recognition and Translation by Partial Hypothesis Selection

Encoder-decoder models provide a generic architecture for sequence-to-sequence tasks such as speech recognition and translation. While offline systems are often evaluated on quality metrics like word error rates (WER) and BLEU, latency is also a crucial factor in many practical use-cases. We propose three latency reduction techniques for chunk-based incremental inference and evaluate their efficiency in terms of accuracy-latency trade-off. On the 300-hour How2 dataset, we reduce latency by 83% to 0.8 second by sacrificing 1% WER (6% rel.) compared to offline transcription. Although our experiments use the Transformer, the hypothesis selection strategies are applicable to other encoder-decoder models. To avoid expensive re-computation, we use a unidirectionally-attending encoder. After an adaptation procedure to partial sequences, the unidirectional model performs on-par with the original model. We further show that our approach is also applicable to low-latency speech translation. On How2 English-Portuguese speech translation, we reduce latency to 0.7 second (-84% rel.) while incurring a loss of 2.4 BLEU points (5% rel.) compared to the offline system

An Examination of the Contribution of Self-Stimulation on the Recall of Elementary Verbal Operants

Skinner’s (1957) Verbal Behavior has made an impactful contribution to the analysis of verbal behavior in the field of behavior analysis. One noteworthy contribution has been the functional analysis of elementary verbal operants, which include copying text, echoic, taking dictation, textual, and intraverbal operants. However, compared to mands and tacts, these elementary verbal operants are arguably understudied, especially in controlled laboratory settings. Given that verbal operants such as these are considered to be socially significant behaviors for effectively behaving in verbal communities, it may be beneficial to account for often overlooked participating factors related to complex verbal interactions. An empirical analysis of self-stimulation as defined by responding to one’s own stimulus response products in the present study appears to be lacking in the current body of behavior analytic literature. The purpose of this study sought to address this gap by investigating the participation of self-stimulation among verbal operants exhibiting point-to-point correspondence and formal similarity. In the pilot experiment, undergraduate students completed a series of trials in which they (1) performed a response of one of the following verbal operants in which access to response products were unmasked and masked: copying text, echoic, textual, or taking dictation, (2) completed a distractor task, and (3) recalled the initial target response in an intraverbal test. The subsequent online thesis experiment followed a similar set of procedures while accounting for limitations in the pilot experiment, but focused solely on copying text and taking dictation verbal operants. Results of the present study not only suggest that intraverbal performances were not differentially related to accessing stimulus response products between copying text and taking dictation verbal operants but that self-stimulation is functionally related to intraverbal recall upon which reinforcement is contingent

Early Childhood ABA: Issues of Early ASD Detection and Access to Intervention

This paper provides an overview of ABA, summarizes findings from studies of early childhood ABA with a focus on intervention dosage, and addresses the influence of demographics and culture on early ASD detection and access to early childhood ABA intervention. Although, this paper is not inclusive of all the ABA studies conducted between 1987-2007 and beyond, it summarizes the findings of some of the historical studies in early childhood ABA. These historical studies were located through two systematic reviews including studies between the years 1987- 2007 and selected if they met the following criteria: (1) intervention was based on behavioral principals (2) participants were five years of age or younger at the onset of intervention (3) intervention was in-home or clinic-based (4) utilized a group research design. A total of seven studies met the inclusion criteria. All seven studies reported increasing intellectual, educational, and behavioral gains for children with ASD. However, three of the studies did not report significant differences across all outcome measures favoring the treatment group. The seven studies reported mixed findings regarding treatment dosage with weekly treatment dosage ranging from 40 to 19.45 hours. Additional findings indicated that demographics and culture should be considered as they influence the early detection of ASD and access to intervention. Based on these findings, future research should further investigate how these variables along with others moderate or mediate early childhood ABA outcomes associated with early ASD detection and access to intervention