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This paper aims to give an overview on four empirical studies which explored the impact of background speech on cognitive performance and subjectively perceived disturbance. Background speech is the most serious noise problem in shared-room and open-plan offices for employees who are supposed to do silent, concentrated work. Different measures of acoustic office optimization, as well as the outstanding role of the intelligibility of background speech for its disturbance impact, are empirically evaluated.

The article provides a synopsis describing the core empirical results of four of our empirical studies. A survey study among office employees (n = 659) explored the subjective importance of office acoustics. Three experimental studies (n1 = 20; n2 = 30; n3 = 24) evaluated the effects of reduced background speech level, play-back of partial maskers and reduced speech intelligibility on cognitive performance and subjective ratings.

Background speech is subjectively perceived as a severe problem, and the different noise abatement measures affect objective performance and subjective ratings differently. Speech intelligibility is – besides level – a key determinant for the acoustic optimization regarding these two dimensions.

Practitioners are encouraged to apply the findings and described measures when planning and/or evaluating open-plan offices.

It is concluded that different acoustically efficient measures need to be combined to minimize the negative effects of background speech on cognitive performance and subjectively perceived disturbance. The aspired set value for open-office concepts is the lowest possible sound level with a bad intelligibility of the background speech at the same time.

The synopsis of several empirical studies allows deriving comprehensive and well-founded information for practitioners involved in the evaluation and/or design of offices environments.

The purpose of this paper is to show how the performance of the personnel can be negatively affected by conversations, adjacent to the working space, in an open‐plan office environment.

Using two scientific mathematical models it is possible to quantify the performance losses, as a result of adjacent conversations, with various desk layouts in an open‐plan office.

The results obtained from the underlying Finnish study can be improved by applying a regression analysis to the recorded research results. The modified deviation formula not only corresponds more closely to the research results, but also produces a better translation of the speech intelligibility index to the intelligibility qualifications, as shown in the guideline NPR 3438.

It is reasonable to conclude that performance loss, as a result of a poor acoustic situation, can be related to the speech intelligibility in a space. The relationship between the speech intelligibility index and performance loss makes it possible to design on the basis of productivity improvement, resulting in a comfortable acoustic working environment and a consistent financial advantage for the organisation.

As oral communication in higher education is vital, good classroom acoustics is needed to pass the verbal message to university students. Non-auditory factors such as academic language, a non-native educational context and a diversity of acoustic settings in different types of classrooms affect speech understanding and performance of students. The purpose of this study is to find out whether the acoustic properties of the higher educational teaching contexts meet the recommended reference levels.

Background noise levels and the Speech Transmission Index (STI) were assessed in 45 unoccupied university classrooms (15 lecture halls, 16 regular classrooms and 14 skills laboratories).

The findings of this study indicate that 41 classrooms surpassed the maximum reference level for background noise of 35 dB(A) and 17 exceeded the reference level of 40 dB(A). At five-meter distance facing the speaker, six classrooms indicated excellent speech intelligibility, while at more representative listening positions, none of the classrooms indicated excellent speech intelligibility. As the acoustic characteristics in a majority of the classrooms exceeded the available reference levels, speech intelligibility was likely to be insufficient.

This study seeks to assess the acoustics in academic classrooms against the available acoustic reference levels. Non-acoustic factors, such as academic language complexity and (non-)nativeness of the students and teaching staff, put higher cognitive demands upon listeners in higher education and need to be taken into account when using them in daily practice for regular students and students with language/hearing disabilities in particular.

Some facilities managers will be in the position of adapting existing space to cope with changing needs, while others will be concerned with drawing up specifications for new spaces. Both need practical advice from the acoustician about how to deal with existing problems of speech and noise in rooms. Many offices facing crises in space planning and in staff management are also faced with difficulties concerning speech acoustics, particularly in the areas of speech intelligibility, speech privacy and noise. Research into these aspects of room acoustics by the present author has resulted in an improved approach to measuring the information characteristics of both speech and noise in rooms. A design index is described for predicting the intelligibility of speech and is illustrated by a typical example of conditions in the open plan office. Advice is also needed on the implications of new speech technologies (speech synthesis and speech recognition) on office layout. These new products have already been in everyday use for over 10 years in some office environments and are becoming more commonplace. It is shown that as the new, speech‐driven equipment is taken up, the problems of containing noise in open‐plan spaces will increase, unless speech acoustics in the office is given a new priority.

The purpose of this paper is to systematically map research on the effect of classroom acoustics and noise on high school students’ listening, learning and well-being, as well as identify knowledge gaps to inform future research.

This scoping review followed the PRISMA-ScR protocol. A comprehensive search of four online databases (ERIC, PubMed, Scopus and Web of Science) was conducted. Peer-reviewed papers were included if they conducted a study on the effect of classroom acoustics or noise on students’ listening, learning or well-being; had a clear definition of the noise level measurement; were conducted with high school students; and had the full text in English available.

In total, 14 papers met the criteria to be included in the review. The majority of studies assessed the impact of noise on students’ listening, learning or well-being. Overall, the results showed that higher noise levels have a negative effect on students’ listening, learning and well-being. Effects were even more pronounced for students who were non-native speakers or those with special educational needs such as hearing loss. Therefore, it would be beneficial to limit unnecessary noise in the classroom as much as possible through acoustic insulation, acoustic treatment and classroom management strategies.

This paper is the first review paper to synthesize previous research on the effect of classroom acoustics and noise on high school students’ listening, learning and well-being. It provides an analysis of the limitations of existing literature and proposes future research to help fill in these gaps.

Assessing learning outcomes for students who are d/Deaf or hard of hearing presents ongoing challenges given the largely verbal nature of classrooms and the presentation of information. Educators should carefully consider several factors when assessing their students who are d/Deaf or hard of hearing. Those factors include, but are not limited to: the format of the assessment, the format in which the student is expected to respond, classroom acoustics, as well as how to continue monitoring learning outcomes based on classroom instruction.

This paper describes the development process of a mobile Voice User Interface (VUI) for Korean users with dysarthria with currently available speech recognition technology by conducting systematic user needs analysis and applying usability testing feedback to prototype system designs.

Four usability surveys are conducted for the development of the prototype system. According to the two surveys on user needs and user experiences with existing VUI systems at the stage of the prototype design, the target platforms, and target applications are determined. Furthermore, a set of basic words is selected by the prospective users, which enables the system to be not only custom designed for dysarthric speakers but also individualized for each user. Reflecting the requests relating to general usage of the VUI and the UI design preference of users through evaluation of the initial prototype, we develop the final prototype, which is an individualized voice keyboard for mobile devices based on an isolated word recognition engine with word prediction.

The results of this paper show that target user participation in system development is effective for improving usability and satisfaction of the system, as the system is developed considering various ideas and feedback obtained in each development stage from different prospective users.

We have developed an automatic speech recognition-based mobile VUI system not only custom designed for dysarthric speakers but also individualized for each user, focussing on the usability aspect through four usability surveys. This voice keyboard system has the potential to be an assistive and alternative input method for people with speech impairment, including mild to moderate dysarthria, and people with physical disabilities.

This study aims to examine activity-related sound levels and pupils’ perceptions of the acoustic environment in two classrooms, one of which was a traditional classroom (Reference classroom, reverberation time (RT) 0.54 s) and the other a refurbished classroom (Demo classroom, RT 0.32 s).

Three types of data were gathered: room acoustic measurements, activity sound levels during different activities and pupils’ subjective experience concerning factors related to acoustics. Pupils, 10–11 years old (N = 34), estimated their subjective experience in general and after four test lessons. Teachers planned the test lessons to have four different lesson types: quiet work, one-person speaking, group work and activity-based work. The sound levels of activities were measured during the test lessons.

The activity sound levels were 2–13 dB L_Aeq lower in the Demo classroom than in the Reference classroom, depending on lesson type. Pupils were less annoyed by noise in the Demo than in the Reference classroom. Pupils’ speech was the most annoying sound source. More pupils were annoyed by it in the Reference classroom (65%) than in the Demo classroom (15%). Hearing the teacher while not seeing her face, concentrating on teaching and sitting in one’s place were estimated easier in the Demo classroom than in the Reference classroom.

This study offers a new approach using test lessons for studying activity sounds in schools. Activity sounds and their annoyance can be significantly diminished by classroom refurbishments.

Dysarthria is a neuromotor speech disorder caused by neuromuscular disturbances that affect one or more articulators resulting in unintelligible speech. Though inter-phoneme articulatory variations are well captured by formant frequency-based acoustic features, these variations are expected to be much higher for dysarthric speakers than normal. These substantial variations can be well captured by placing sensors in appropriate articulatory position. This study focuses to determine a set of articulatory sensors and parameters in order to assess articulatory dysfunctions in dysarthric speech.

The current work aims to determine significant sensors and parameters associated using motion path and correlation analyzes on the TORGO database of dysarthric speech. Among eight informative sensor channels and six parameters per channel in positional data, the sensors such as tongue middle, back and tip, lower and upper lips and parameters (y, z, φ) are found to contribute significantly toward capturing the articulatory information. Acoustic and positional data analyzes are performed to validate these identified significant sensors. Furthermore, a convolutional neural network-based classifier is developed for both phone-and word-level classification of dysarthric speech using acoustic and positional data.

The average phone error rate is observed to be lower, up to 15.54% for positional data when compared with acoustic-only data. Further, word-level classification using a combination of both acoustic and positional information is performed to study that the positional data acquired using significant sensors will boost the performance of classification even for severe dysarthric speakers.

The proposed work shows that the significant sensors and parameters can be used to assess dysfunctions in dysarthric speech effectively. The articulatory sensor data helps in better assessment than the acoustic data even for severe dysarthric speakers.

This chapter provides an overview of the Department of Defense (DoD) laboratory structure to help equipment designers, modelers, and manufacturers determine where research, testing programs, or relevant findings can be found. The chapter includes a discussion of the performance measures and metrics typically used in DoD laboratories and concludes by considering the current state-of-the-art as well as the state-of-the-possible for human performance measurement.