soundreproduction that it ends up overshadowing other facets – such as loudness. I would also argue that the history of soundreproduction is not, despite what much academic literature might suggest, a story about the problem space of fidelity. Not exclusively, anyway. Soundreproduction obviously raises some provocative questions about the relationship between originals and copies (Sterne 2003), about speech and writing (Gitelman 2000), presence and absence (Peters 2004), the real and the symbolic (Kittler 1999), otology and ontology (Connor 1997). These are instances and extensions of ‘the paradoxes of phonography’ (Eisenberg 1987, p. 158). As a term, phonography is difficult to define precisely, and the use of it cannot be assigned to any one scholar. In general, though, it is meant as a shorthand way of pointing to a kind of acoustic modernity, in which the development of soundreproduction offered not only new technological possibilities but also new epistemological problems, both of which helped redefine relationships between human consciousness and communication, on the one hand, and the world of sound, on the other. In other words, phonography refers to ‘a period in our relation to music . . . marked by a distinct set of attitudes, practices, and institutions made possible by . . . the phonograph’ (Rothenbuhler and Peters 1997, p. 242) as well as ‘an anthropological revolution in human history – not just another in a series of technological innovations but one which profoundly interrupts and problematises what it means to be human’ (Engh 1999, p. 54).
This paper has highlighted the need for HE courses that include the area of soundreproduction to have a clear eye on the needs of industry and feature learning activities that engage students in realistic and industry-relevant ways. If the evidence from this study is representative of other students in HE institutions then it could be surmised that many students on these types of courses are already engaging with their chosen area of industry. Course providers will therefore need to consider ways of enhancing this sort of activity both within the curriculum and methods of teaching, which could include a requirement to undertake shadowing of professionals or location work which could also prove useful for students who are not currently engaged with industry work.
A basic tenet of soundreproduction is the concept of ‘fidelity’, meaning as many aspects of the acoustical context of an original recording be reproduced as faithfully as possible to please the ‘critical listener’. The point of reference may either be the studio control room or a live venue, and deviation in reproduction may be objectively quantified within limits. More recently the importance of quantifying subjective response so as to build a point of reference based on preference data has been introduced. An alternative model considers the critical listener as a participant in the soundreproduction process, for whom the sensation of ‘ideal reproduction’ is malleable and that can take many forms. From this standpoint, the taxonomy of attributes such as timbre, level and spatial reproduction fall short of any point of reference in many real-world audio reproduction contexts, and yet the critical listener is satisfied. Furthermore there is no reason to assume that preference is ‘time invariant’, although this is frequently assumed. Acoustic analyses of loudspeaker playback in typical rooms are suggestive of spatial characteristics that are the result of conscious or unconscious participation by the end user. It is suggested that there are spatial attributes that fall out of this participation that are currently undervalued in current research.
Crosstalk cancellation system (CCS) plays a vital role in spatial soundreproduction using multichannel loudspeakers. However, this technique is still not of full-blown use in practical applications due to heavy computation loading. To reduce the computation loading, a bandlimited CCS is presented in this paper on the basis of subband filtering approach. A pseudoquadrature mirror filter (QMF) bank is employed in the implementation of CCS filters which are bandlimited to 6 kHz, where human’s localization is the most sensitive. In addition, a frequency-dependent regularization scheme is adopted in designing the CCS inverse filters. To justify the proposed system, subjective listening experiments were undertaken in an anechoic room. The experiments include two parts: the source localization test and the sound quality test. Analysis of variance (ANOVA) is applied to process the data and assess statistical significance of subjective experiments. The results indicate that the bandlimited CCS performed comparably well as the fullband CCS, whereas the computation loading was reduced by approximately eighty percent.
HOA only allows for error-free soundreproduction in a very restricted area, called the sweet spot, cf.  and . Three-dimensional holophony is not feasible for the entire auditorium. For this reason, energy-preserving decoding methods have been recently presented , which interpret Ambisonics decoding as a panning law and preserve the energy over the entire angular domain. They have been shown to be numerically stable and feasible on the hemisphere. Alternative methods for hemispherical Ambisonics decoding, e.g. using a modified set of basis functions, have been presented in . The horizontal 280-loudspeaker array provides a very dense grid of speakers and is used for two- dimensional sound field reproduction with both WFS and HOA.
Human safety is the most important issue in disaster management. Speech is a sound signal containing information that is easily and quickly understood by humans. Using speech as sound signage in emergency systems can effectively in- crease human safety in low or poor visibility conditions such as in smoke-filled situations. However, reflections of sound through walls, floor surfaces, and ceilings will affect clarity of speech. Unfortunately, because of the characteris- tics of soundreproduction systems, a single loudspeaker propagates sound waves omni-directionally at low frequencies. This paper proposes a simple multiple-loudspeaker system for reproducing sound with uni-directional characteristics. The proposed system consists mainly of a primary loudspeaker for introducing sound in the desired beam, a secondary loudspeaker for reducing gain in the undesired direction, and digital filters. An adaptive finite-impulse-response (FIR) filter is used to produce the controlling sound by implementing a filtered-x least-mean-square algorithm, and a delay filter for adjusting the time alignment of sound propagation between primary and secondary sources at the control point. Several operational conditions for illustrating real situations and reflections were considered in an anechoic chamber. Experimental results show the directivity patterns of the proposed multiple-loudspeaker system for the required condi- tions. In a low frequency range, the system is able to control unidirectional propagation; there is a sound beam in the desired direction and, conversely, reduction of gain in the undesired direction around the control point.
Care about sound
When people think of a place to recuperate from illness or medical treatment, most visualize places that are quiet and peaceful. This is in stark contrast to the typical modern hospital, where noise from beepers, alarms, equipment, telephones, voices and more fill the normal sound environment. Hospital noise - one of the biggest complaints of patients - should no longer be ignored. Especially as a good sound environment becomes indispensable in the context of intense, accurate communication while applying stricter rules regarding patient privacy and patient data security.
Growth and reproduction are intimately related. Cells duplicate through binary fission. As the cell acquires more molecules, it enlarges, duplicates its DNA and then splits in two. There are different types of asexual reproduction, of which binary fission is the simplest and the most common way through which the majority of organisms including the archaea, bacteria and protists replicate. It is however not far different from normal growth that occurs in multicellular organisms where cells subdivide to form copies of themselves. This is how embryos develop, injuries heal, growth occurs and cells are replaced. Multicellular organisms originated because of a small mutation which enabled newly formed cells to adhere to each other instead of splitting up. In this way, plants, fungi and animals originated from single-celled ancestors (Durand 2013). Several organisms such as slime mould can fluctuate between a single cell and a colonial state. It is important to note however that liver cells make copies of liver cells and epithelial cells come from epithelial cells, but if one goes back to the original early embryo, different cells (blastomeres) will give rise to quite different and distinct organs with unique tissue types. The sponge may consist of aggregates of similar cells, but all animals more evolutionarily advanced than the sponge consist of tissues and organs. The embryo of multicellular animals beyond the grade of a sponge consist shortly after the original cleavage of cells that are not merely identical duplicates of the original zygote but distinctly different and fated to become different organs. In other words, in the early embryo, mitotic cleavage gives rise to cells different than the original which would fit the theory of allopoiesis.
Saxophone sounds were binaurally recorded with an artificial head (Head Acoustics HMS III), and played back to the subjects in the listening tests by using equalised headphones . To get sounds with variations typical of saxophone sounds recordings were made by two different saxophone players each playing two alto saxophones of different brands. This gave four possible combinations. The saxophone players were asked to play a jazz standard (“I Remember Clifford”) parts of which were used. By having them play an entire piece it was felt the notes used would be “normal”. Recording was carried out in a small concert hall intended for jazz and rock music. Each musician stood in the middle of the stage while they performed. The artificial head was placed 5 m in front of the saxophone player facing them. The saxophone player tuned their instrument before the recording and they were given a tempo by a metronome. Both players were instructed to play a mezzo forte. Both were studying saxophone at the university level.
We present an approach to content-based sound retrieval using auditory models, self-organizing neural networks, and string matching techniques. It addresses the issues of spotting perceptually similar occurrences of a particular sound event in an audio document. After introducing the problem and the basic approach we describe the individual stages of the system and give references to additional literature. The third section of the paper summarizes the preliminary experiments involving auditory models and self- organizing maps we carried out so far, and the final discussion reflects on the overall concept and suggests further directions.
Common porous absorbers include carpets, draperies, spray-applied cellulose, aerated plaster, fibrous minerals wool and glass fibres, open-cell foam, and cast porous ceiling tiles. Generally, all of these materials allow air to flow into a cellular structure where sound energy is converted into heat. Initially, there is the viscous loss as air is pumped into and out of the open porous structures. Sealing the surfaces with paint films greatly reduces the absorption. There is also the damping of the material. Damping refers to the capacity of the material to dissipate energy. It measures the fractional loss of energy of a wave per cycle, as it propagates within the material itself. Damping in metals and ceramics is 10 -6 -10 -2 , in polymers it’s about 10 -2 -0.2. Porous absorbers are the most commonly used sound absorbing materials. Fabric applied directly to a hard, massive substrate such as plasterboard does not make an efficient sound absorber due to the very thin layer of fibre. Thicker materials generally show greater damping .
The first experiment sought to reproduce the soundscape dimensions found by Kang in the field, but in a different city, some years later, using a spatial audio system rather than in-situ exposure. Recordings were made of the soundscape in four urban locations in Manchester city centre (in the UK). A soundfield microphone was used to make first-order ambisonic recordings. Two of the locations were at opposite ends of St Ann’s Square, a pedestrianised shopping area bounded on one side by a cobbled road. The first recording (A) was near the cobbled road, and the second (B) was near a busking musician. (St Ann’s Square was much studied by the Positive Soundscape Project .) The third location was a pedestrianised underpass, and the fourth was on a busy road with a railway bridge going over it. Figure 1 shows snapshots of the four locations. The recordings were reproduced using an eight- loudspeaker three-dimensional first-order ambisonic system in a semi-anechoic chamber at Salford University. Sound levels at the listener’s position were the same as at the point of recording (L Aeq ). One 30-second recording was used for each of the four locations. Fifteen
In the SNA the production boundary includes: “The production of all goods or services that are supplied to units other than their producers, or intended to be so supplied, including the production of goods or services used up in the process of producing such goods or services” (SNA 2008, 98; our italics). This production relies on social reproduction (and we argue depletion). We also know that “Economic production may be defined as an activity carried out under the control and responsibility of an institutional unit that uses inputs of labour, capital, and goods and services to produce outputs of goods or services. There must be an institutional unit that assumes responsibility…A purely natural process without any human involvement or direction is not production in an economic sense” (SNA 2008, 97-98; our italics). Now, what we have been exploring is whether the non-recognition of aspects of work (social reproduction) of an institutional unit – the household 7 - also leads to non-recognition of the ‘goods and services used up’ in this process. This non-recognition then contributes to depletion by taking social reproduction and its costs for granted and leaving these unmeasured. Thus non-valuation of both work and the resources that are used up or that ‘decrease seriously’ need to be accounted for if we are to address the issue of depletion of those engaged in social
commonly held to be reproduction, where (1) an entity produces a new one and (2) the produced entity is similar in some respect to its producer. Both roles establish a lineage between the two concerned entities. In the first case, there is a productive lineage where an entity is the parent of another, its offspring, if it produced it. In the second case, the lineage is one of entities “passing on their traits” or “transmitting some characteristic” to one another, the sequence of such events constituting the lineage of inherited similarity. While both types of lineages are often conflated together, as it is the case with reproduction, the recent recognition that there are multiple inheritance systems with asymmetric