Use Of Amplification Systems Research Articles

Teacher’s vocal health: Voice application systems and other work-related factors

School teachers’ voice problems are widespread and influence the learning process. Voice amplification systems in classrooms are a common response and a preventative strategy. The primary purpose of this study was to (1) determine the relationship between teacher vocal fatigue and use of classroom amplification; and (2) identify factors influencing amplification usage. Teachers throughout the US completed questionnaires regarding vocal health, classroom conditions, lifestyle habits, and access to and use of vocal amplification systems. Responses indicated that biological female teachers who used voice amplification or taught grades kindergarten to middle school were more likely to report higher levels of vocal fatigue. Further, teachers with access to amplification systems were more likely to use them if they were teachers in lower grade levels, who smoked occasionally, drank alcohol frequently, and taught in larger capacity classrooms. In conclusion, it maybe that those using the amplifications are using them because of pre-existing voice issues. Finally, the work-related factors associated with the use of amplification systems (e.g., grade level, classroom capacity) may be indicators of adjustments to reduce the occurrence of voice problems among teachers. Ongoing studies reviewing the available classroom amplification equipment and use from a school administrators perspective will be discussed.

Factors Influencing Teachers’ Experience of Vocal Fatigue and Classroom Voice Amplification

Voice disorders among teachers are widespread. Teachers' voice problems have been shown to influence the teaching-learning process, thereby impeding students' academic performance. Voice amplification has been used as a preventative strategy to avoid voice problems and as a means of augmenting student reception of a teacher's voice. However, the relationship between perceived vocal fatigue and amplification use has not been established, nor have factors been identified which may be associated with the use of voice amplification in the classroom. This research has two aims: (1) determine the relationship between self-reported vocal fatigue and self-reported teachers' use of sound field amplification in the classroom; and (2) identify which factors are related with the use of amplification systems among the participating teachers. Paper and online surveys were provided to teachers throughout the United States. These surveys contained the 19-question Vocal Fatigue Index (VFI), in addition to other questions regarding health-related conditions and lifestyle habits of respondents. Access to and use of amplification systems, as well as other work-related factors that might influence the use of such systems were detailed by the respondents. Regardless of grades levels or measured factors, teachers who reported using amplification systems were more likely to report higher levels of vocal fatigue. Teachers who taught in lower grade levels or in larger capacity classrooms not only reported a greater likelihood of using the systems more frequently, but also reported a greater access to amplification systems. Overall, less than 40% of teachers had access to an amplification system. Teachers of lower grades reported having the least access. Our results suggest an association between teachers' use of voice amplification systems and vocal fatigue. In addition, some work-related factors (eg, grade level, classroom capacity) were associated with the use of amplification systems. The results can be beneficial to teachers, school administrators, lawmakers and health professionals to more efficiently use diminishing educational resources in a targeted fashion to better train and potentially reduce the occurrence of voice problems among teachers.

Do Age and Linguistic Status Alter the Effect of Sound Source Diffuseness on Speech Recognition in Noise?

One aspect of auditory scenes that has received very little attention is the level of diffuseness of sound sources. This aspect has increasing importance due to growing use of amplification systems. When an auditory stimulus is amplified and presented over multiple, spatially-separated loudspeakers, the signal’s timbre is altered due to comb filtering. In a previous study we examined how increasing the diffuseness of the sound sources might affect listeners’ ability to recognize speech presented in different types of background noise. Listeners performed similarly when both the target and the masker were presented via a similar number of loudspeakers. However, performance improved when the target was presented using a single speaker (compact) and the masker from three spatially separate speakers (diffuse) but worsened when the target was diffuse, and the masker was compact. In the current study, we extended our research to examine whether the effects of timbre changes with age and linguistic experience. Twenty-four older adults whose first language was English (Old-EFLs) and 24 younger adults whose second language was English (Young-ESLs) were asked to repeat non-sense sentences masked by either Noise, Babble, or Speech and their results were compared with those of the Young-EFLs previously tested. Participants were divided into two experimental groups: (1) A Compact-Target group where the target sentences were presented over a single loudspeaker, while the masker was either presented over three loudspeakers or over a single loudspeaker; (2) A Diffuse-Target group, where the target sentences were diffuse while the masker was either compact or diffuse. The results indicate that the Target Timbre has a negligible effect on thresholds when the timbre of the target matches the timbre of the masker in all three groups. When there is a timbre contrast between target and masker, thresholds are significantly lower when the target is compact than when it is diffuse for all three listening groups in a Noise background. However, while this difference is maintained for the Young and Old-EFLs when the masker is Babble or Speech, speech reception thresholds in the Young-ESL group tend to be equivalent for all four combinations of target and masker timbre.

Factors associated with school participation among students with hearing loss

The aim of this study is to explore teachers’ views on school participation of students with hearing loss (HL) and to examine the association between students’ school participation and factors related to the framework of the International Classification of Functioning, Disability and Health for Children and Youth (ICF-CY). A total of 167 teachers participated in the study. Structural equation modelling was performed to explore relationships among the factors. The teachers considered the students to be socially included and to participate academically almost at the same level as their typical classmates. A multifaceted interaction between ICF-CY factors and students’ participation in academic activities was found. Personal factors such as ‘academic skills and motivation’ explained most of the variance in academic participation, and were also associated with activity and environmental factors. Efforts to understand their classmates directly and indirectly associated with academic participation. Students with mild and severe HL appeared to have same level of participation rate. The parents’ involvement in their children’s schooling and the use of amplification systems were related to academic participation but not to social participation. A few factors associated with social participation; in those cases, having other disabilities in addition to HL explained most of the variance.

Next steps toward improving classroom acoustics for all.

For the past ten years, the ASA has been very influential in the improvement of classroom acoustics, especially with the adoption of ANSI S12.60‐2002. In fact, we have been a part of a worldwide effort to improve the learning environments for children, thanks in large part to the efforts of Nixon. Even after the adoption of the standard, we must still be involved in local and state policy decisions involving classroom acoustics, especially in urban districts with older school buildings, diverse students, and declining enrollment. We can and should form partnerships with personnel in local school districts to evaluate and fix acoustical problems in schools. Recently we worked with a local urban school district to evaluate schools and determine the best investment for improving acoustics. In some schools, sustained noise levels were well over 65 dBA, largely because of poor quality doors and windows that allowed in high levels of external noise from hallways and outside. Solutions included: damping ventilation vibration, adding door seals, and judicious use of amplification systems when higher‐signal levels were needed. In most cases, reducing noise problems at the source was the best investment of district funds.

The effect of amplification on children's performance in the classroom

The use of amplification systems in the classroom has the potential to reduce the impact of poor classroom acoustics for typically developing pupils and those with special educational needs (SENs). The immediate benefits of amplified acoustic signals on the performance of 253 primary school children, including 24 children with special needs, were examined. All participants were familiar with the use of the amplification systems. Children's performance was assessed on two verbal measures (spelling and oral comprehension) and one non‐verbal measure, using a balanced repeated measures design. It was predicted that the effects of amplification would be evident for spelling and oral language comprehension, but that there would be no discernable effect on speed of processing. Children with SEN were expected to have an added advantage with amplification. The predictions were partially supported. Both gain score analysis and ANOVAs of performance scores with amplification, controlling for performance without ampl...

Imaging Folate Binding Protein Expression with MRI

The ability to manipulate genes coupled with having mapped the genome of many species opens up the postgenomic era. One now needs the ability to study the effects of the molecules encoded by these genes on an animal’s development, biochemical processes, and physiological make up in-vivo. Such studies require in-vivo techniques capable of imaging molecular expression. Only MRI has the potential and capabilities of imaging anatomy, function, and molecular expression. One type of functional and molecular MR imaging uses contrast agents. MR techniques require the use of amplification systems. For affinity based agents the amount of reporter molecule required is regulated by the agent’s relaxivity, or efficiency of reporting, and the number of targeted molecules expressed. In this report we demonstrate the use of a general amplification technology with the specific example of imaging folate binding protein expression. We demonstrate the ability to detect expression of the high affinity folate receptor in human tumor xenografts in-vivo. This particular agent has the potential to play a role in screening for and monitoring therapy of ovarian tumors. MATERIALS AND METHODS

Hearing Impairment in Older Adults: New Concepts

To review present information about the epidemiology, etiologies, pathogenesis, evaluation, and quality of life aspects of hearing loss and to present an approach to rehabilitation for hearing loss in older adults. A survey of recent findings on the problem of hearing loss in older adults, efficacy of intervention with amplification, and new developments in intervention strategies. The complex nature of hearing problems in older adults involves changes in the auditory periphery as well as in the central mechanisms for processing sound input. These changes affect the social and emotional impact of the hearing disorder. The importance of understanding the many implications of hearing loss on quality of life is emphasized. Both older adults and immediate family members need information and advice about the consequences of age-related hearing loss. The physician has a key role in helping them to overcome negative attitudes toward a hearing handicap. For most older persons, hearing aids alleviate many of the handicaps of hearing impairment. For some older persons who do not benefit adequately from conventional hearing aids, assistive listening devices may be helpful. Many old persons and their relatives are reluctant to confront the reality of hearing handicap and try to hide the fact that they need sound amplification. One important future direction is to foster acceptance of hearing loss and to support the more open use of amplification systems.

Nucleic acids in mummified plant seeds: biochemistry and molecular genetics of pre-Columbian maize

Nucleic acids fractions were isolated from pre-Columbian maize seeds and characterized using different approaches such as polyacrylamide gel electrophoresis, anti-DNA antibody binding, HPLC fractionation, molecular hybridization with cloned genes, and DNA amplification by the polymerase chain reaction. The nucleic acids were found to be very depolymerized (less than or equal to 140 base pairs in length) and composed mainly of ribosomal RNA. Despite the very low amount and degree of polymerization of seed DNA, specific maize nuclear Mu1, Mu4, Mu8 and, possibly, Mu5 element components could be detected, thanks to the use of amplification systems as short as 90 bp. The results suggest that evaluation of the relative proportions of Mu-type element components and, possibly, other maize genomic components in single mummified kernels, may offer a new key to the study of ancient maize populations.