Tissue-conducted spatial sound fields

We describe experiments using multiple cranial transducers to achieve auditory spatial perceptual impressions via bone (BC) and tissue conduction (TC), bypassing the peripheral hearing apparatus. This could be useful in cases of peripheral hearing damage or where ear-occlusion is undesirable. Previous work (e.g. Stanley and Walker 2006, MacDonald and Letowski 2006)1,2 indicated robust lateralization is feasible via tissue conduction. We have utilized discrete signals, stereo and first order ambisonics to investigate control of externalization, range, direction in azimuth and elevation, movement and spaciousness. Early results indicate robust and coherent effects. Current technological implementations are presented and potential development paths discussed

Hearing Without Ears

We report on on-going work investigating the feasibility of using tissue conduction to evince auditory spatial perception. Early results indicate that it is possible to coherently control externalization, range, directionality (including elevation), movement and some sense of spaciousness without presenting acoustic signals to the outer ear. Signal control techniques so far have utilised discrete signal feeds, stereo and 1st order ambisonic hierarchies. Some deficiencies in frontal externalization have been observed. We conclude that, whilst the putative components of the head related transfer function are absent, empirical tests indicate that coherent equivalents are perceptually utilisable. Some implications for perceptual theory and technological implementations are discussed along with potential practical applications and future lines of enquiry

Inside-outside: 3-D music through tissue conduction

Eliciting an auditory perception by means of mechanical transduction bypassing the peripheral hearing apparatus has been recorded as early as the 16th century. Excluding its audiometric use to assess ear pathology, bone and soft tissue conduction has received very little interest until the last two decades. Previous work during this time (Stanley and Walker 2006, MacDonald and Letowski 2006) has indicated robust lateralization is feasible via mechanical transduction. We have extended this, adding the front-back and up-down axes

Hypoadrenocorticism in an aged cat

A 13-year-old, female, neutered, domestic longhair cat was referred to the hospital with a two-month history of fluctuating weakness, lethargy, inappetence and intermittently soft stools. Physical examination noted variable mentation, mild tachycardia with poor pulse quality and a body condition score of 1/9. In-house haematology and biochemistry abnormalities included a mild neutrophilia, hyponatraemia, and decreased Na:K ratio of 24 and isosthenuric urine (1.012). The cat was admitted to the hospital for intravenous fluid therapy and management of its electrolyte abnormalities. A low basal cortisol (36 nmol/l) was found on analysis of a stored serum sample, and further investigations confirmed the diagnosis of hypoadrenocorticism. Treatment was implemented initially with hydrocortisone and dexamethasone and continued long term with desoxycorticosterone pivalate and oral prednisolone. More than one year since diagnosis, the cat is clinically well and stable on treatment

The use of therapeutic untruths by learning disability nursing students

Background: The use of therapeutic untruths raises a number of ethical issues, which have begun to be explored to some extent, particularly in dementia care services, where their use has been found to be high. Little is known, however, about their use by health professionals working in learning disability services. Research question: The study aimed to explore the frequency of use of therapeutic untruths by student learning disability nurses, and by their colleagues; how effective the students perceived them to be as a means of responding to behaviours that challenge; and their level of comfort with using them. Research design: A correlational design was used to gather data from an online version of the Best Interest Scale, adapted for a learning disability context. Participants were 30 learning disability student nurses (female = 28, ages 18–48 years, M = 26.8, standard deviation = 7.3) studying at a university in the North-East of England. Ethical considerations: The study was reviewed and received ethical approval from the first author’s university ethics committee. Findings: Overall, 96% of participants reported using therapeutic untruths. ‘Omission’ was the most frequently used type of therapeutic untruths, the most effective and the type that the students felt most comfortable using. Frequency of use of therapeutic untruths correlated significantly and positively with perceived effectiveness and the level of comfort that the students felt when using them, for all types of therapeutic untruths. Conclusion: The use of therapeutic untruths by the student nurses was consistent with that found in research in dementia care services in the United Kingdom and abroad. Further research to explore the generalisability of the results to the wider context of learning disability services is needed. The study highlights that there may be a need for more formal guidance and educational input to student nurses in the use of therapeutic untruths with people with a learning disability

Groundwater Heat Pump Suitability Mapping: Theory, Procedure And Assessment

Ground water used in conjunction with a heat pump is a cost effective source of heating and cooling. Regional planning for ground water heat pumps is a new direction in energy planning.;Use of ground water for heating and cooling should be based on the potential for the landscape to support a heat pump system. Some locations are better suited for ground water heat pump placement than others. A method to assess and categorize geographic areas according to their capabilities to support the use of ground water source heat pumps is presented. Landscape parameters such as ground water availability, topography, bedrock geology, geomorphology, soil, and soil percolation rates are assessed to classify land for heat pump suitability.;The method of appraising suitability involves placing the seven parameters into a ground water heat pump suitability matrix. Each parameter is assigned an importance unit value which remains fixed throughout the classification. Parameter weightings vary for 1 sq km cells and are dependent upon the quality of the parameter to support a successful heat pump site. A suitability rating is calculated for each cell by multiplying the Parameter Importance Unit values of each cell by the assigned weightings. The values of the seven parameters are summed to obtain a rating for each cell. The ratings are classed as High, Moderate, or Low Suitability.;The classification is tested on the 1,400 sq km Region of Waterloo, Ontario, Canada. Results are presented in the form of a map which is intended to serve as a basis for regional planning of ground water heat pump systems. The results for the Region of Waterloo study show 19 per cent of the Region is of High, 41 per cent is Moderate, and 40 per cent is Low Suitability.;The classification system should advance the orderly development of ground water heat pump systems. The classification method is transferable because of the method of parameter importance assessment. The physical diversity from region to region can be considered by assigning a numerical weighting to each of the seven parameters.;If a regional view of energy use can be seen prior to urban development, wise ground water use and re-use can be considered. Wise ground water use implies both maximization of the resource potential in places where it benefits can outweigh those of other energy systems, and protection of the ground water resource from overuse and deteriorating quality

Month of birth and its relationship to streaming in the primary school

This study is concerned with an investigation into the relationship between month of birth and stream placement in the primary school. It is particularly concerned with the possibility that, where traditional streaming is implemented, there may be an under-estimation of the younger children in a school year age group. Streaming is usually defined as "grouping according to ability with considerations of attainment", but, in practice, only attainment seems to be assessed adequately, and ability tends to be given less attention. In the traditionally streamed primary school, allocation is usually based on attainment level at the time of leaving the infant department. It is possible that some of the younger children in the year group, who have matured less intellectually, and who have had less time in the infant department to benefit from early formal tuition, may be under-estimated and placed in lower streams than their potential would warrant. In the study 1000 children from 5 schools, 500 in the first year of the junior department and 500 in the fourth year, were investigated with respect to Month of Birth, I.Q., and Stream Placement. Results showed that, although, in general, the children were successfully streamed, and although no birth months were superior with respect to intelligence, the younger children tended to be placed more readily in the lower streams. This was the case at first year level but not at fourth year level. Thus, although there was a tendency for early underestimation of the younger children of the school year group, this seemed to be rectified later to a great extent

Sensory augmentation through tissue conduction

One hundred volunteers have undergone short (5 min) listening tests in a novel multi-transducer bone-and-tissue conduction apparatus for spatial audio. The subjects subsequently described their experiences in an unstructured qualitative elicitation exercise. Their responses were aggregated to identify key themes and differences. Emergent themes are: enjoyable, informative, spatial and strange. Tactile supplementation of spatial audio display was noted in a positive light. We note that some spatial attributes are more perceptible than others. The implications for perceptual augmentation are discussed, particularly in relation to conductive hearing deficits. We conclude that the technique has potential for development and discusses future research directions.N/

Investigating spatial music qualia through tissue conduction

A spatial array of vibro-mechanical transducers for bone-and-tissue conduction has been used to convey spatial ambisonic soundscape and spatial musical material. One hundred volunteers have undergone a five-minute listening experiences, then have described the experience in their own words, on paper, in an unstructured elicitation exercise. The responses have been aggregated to elicit common emergent descriptive themes, which were then mapped against each other to identify to what extent the experience was valuable, enjoyable and informative, and what qualia were available through this technique. There appear to some substantive differences between this way of experiencing music and spatial sound, and other modes of listening. Notably, the haptic component of the experience appears potentially informative and enjoyable. We conclude that development of similar techniques may have implications for augmented perception, particularly in respect of quality of life (QoL) in cases of conductive hearing loss.n/