Construction and Characterization of a Portable Sound Booth for Onsite Voice Recording

2011 ◽  
Vol 26 (3) ◽  
pp. 140-145
Author(s):  
Christophe E Jackson ◽  
John T Tarvin ◽  
Paul A Richardson ◽  
Stephen A Watts ◽  
Paul F Castellanos

The negative effects of environmental noise on sound recordings are recognized in the professional literature. Sound booths and anechoic chambers are examples of controlled acoustical environments widely used in research. However, both enclosures are expensive, require substantial space, and are not portable. Our research has been directed to measuring vocal endurance and voice characteristics of singers before and after sustained voice use. Our desire to acquire high-quality onsite recordings necessitated the development of a portable recording environment. In this article, we report the design, construction, and acoustic characterization of a prototype portable sound box (PSB) to acquire high-quality voice recordings in a controlled, portable acoustical measurement. Simulations were conducted to model the intended use of the PSB by voice users, using two acoustic characterization procedures. The first method showed higher intensity variations by region and depth as frequency changed. For the modified method, intensity response was more uniform and displayed less variation with frequency change. Both methods enabled us to (1) refine the onsite recording procedure, (2) provide insight into potential sources of analysis errors, and (3) develop detailed analysis of frequency intensity response affected by equipment variability. We found that it is possible to construct a PSB for onsite high-quality voice recording.

1997 ◽  
Author(s):  
Anatoliy N. Ivakin ◽  
Darrell R. Jackson

1984 ◽  
Vol 49 (8) ◽  
pp. 1846-1853 ◽  
Author(s):  
Karel Hauzer ◽  
Tomislav Barth ◽  
Linda Servítová ◽  
Karel Jošt

A post-proline endopeptidase (EC 3.4.21.26) was isolated from pig kidneys using a modified method described earlier. The enzyme was further purified by ion exchange chromatography on DEAE-Sephacel. The final product contained about 95% of post-proline endopeptidase. The enzyme molecule consisted of one peptide chain with a relative molecular mass of 65 600 to 70 000, containing a large proportion of acidic and alifatic amino acids (glutamic acid, aspartic acid and leucine) and the N-terminus was formed by aspartic acid or asparagine. In order to prevent losses of enzyme activity, thiol compounds has to be added.


Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 237
Author(s):  
Carolina Cardell ◽  
Jose Santiago Pozo-Antonio

The physical–chemical characterization of natural and synthetic historical inorganic and mineral pigments, which may be found embedded in paintings (real or mock-ups), glass, enamel, ceramics, beads, tesserae, etc., as well as their alteration under different decay scenarios, is a demanding line of investigation. This field of research is now both well established and dynamic, as revealed by the numerous publications in high-quality journals of varied scientific disciplines. [...]


2017 ◽  
Vol 122 (8) ◽  
pp. 084103 ◽  
Author(s):  
E. Smirnova ◽  
A. Sotnikov ◽  
S. Ktitorov ◽  
H. Schmidt

2021 ◽  
Vol 13 (15) ◽  
pp. 8235
Author(s):  
Alfredo J. Escribano ◽  
Maria Belen Peña ◽  
Carlos Díaz-Caro ◽  
Ahmed Elghannam ◽  
Eva Crespo-Cebada ◽  
...  

Meat production and consumption have been claimed to have negative impacts on the environment, and even on the consumer’s health. In this sense, alternative sources of protein, mainly meat substitutes and cultured meat, have emerged due to those perceived negative effects. Our paper carries out a choice experiment to analyze the preferences of 444 Spanish consumers and their willingness to pay for plant-based and cultured meats, as compared to conventional meat. Spain was considered of interest for this study due to its significant gastronomic culture, with high-quality meat products that make a great contribution to the economy, meaning that this could be a suitable and also challenging market in which to test alternative sources of protein. The findings show that consumers’ motivations and their interactions with these products are complex. Additionally, a cluster analysis allowed us to identify three types of consumers in terms of preference for these products: price-sensitive millennials, conscious/concerned consumers, and indifferent consumers. Only one group showed some level of acceptance of these alternative products meats.


2021 ◽  
pp. 004051752110238
Author(s):  
Oluwafemi P Akinmolayan ◽  
James M Manimala

Silica nanoparticle-impregnated Kevlar (SNK) fabric has better specific ballistic performance in comparison to its neat counterparts. For multifunctional structural applications using lightweight composites, combining this improved ballistic functionality with an acoustic functionality is desirable. In this study, acoustic characterization of neat and SNK samples is conducted using the normal-incidence impedance tube method. Both the absorption coefficient and transmission loss (TL) are measured in the 60–6000 Hz frequency range. The influence of parameters such as number of layers of neat or treated fabric, percentage by weight of nanoparticle addition, spacing between fabric layers, and residual porosity is examined. It is found that while absorption decreases with an increase in nanoparticle addition for frequencies above about 2500 Hz, increasing the number of layers shifts peak absorption to lower frequencies. By introducing an air-gap behind the fabric layer, dominant low-frequency (1000–3000 Hz) absorption peaks are obtained that correlate well with natural modes of mass-equivalent thin plates. Examining the influence of residual porosity by laminating the SNK samples reveals that it contributes to about 30–50% of the total absorption. Above about 1500 Hz, 3–5 dB of TL increase is obtained for SNK samples vis-à-vis the neat samples. TL is found to increase beyond that of the neat sample above a threshold frequency when an air-gap is introduced between two SNK layers. With an increase in the weight of nanoparticle addition, measured TL tends to be closer to mass law predictions. This study demonstrates that SNK fabric could provide improved acoustic performance in addition to its ballistic capabilities, making it suitable for multifunctional applications and could form the basis for the development of simplified models to predict the structural acoustic response of such nanoparticle–fabric composites.


2021 ◽  
Vol 11 (13) ◽  
pp. 5924
Author(s):  
Elisa Levi ◽  
Simona Sgarbi ◽  
Edoardo Alessio Piana

From a circular economy perspective, the acoustic characterization of steelwork by-products is a topic worth investigating, especially because little or no literature can be found on this subject. The possibility to reuse and add value to a large amount of this kind of waste material can lead to significant economic and environmental benefits. Once properly analyzed and optimized, these by-products can become a valuable alternative to conventional materials for noise control applications. The main acoustic properties of these materials can be investigated by means of a four-microphone impedance tube. Through an inverse technique, it is then possible to derive some non-acoustic properties of interest, useful to physically characterize the structure of the materials. The inverse method adopted in this paper is founded on the Johnson–Champoux–Allard model and uses a standard minimization procedure based on the difference between the sound absorption coefficients obtained experimentally and predicted by the Johnson–Champoux–Allard model. The results obtained are consistent with other literature data for similar materials. The knowledge of the physical parameters retrieved applying this technique (porosity, airflow resistivity, tortuosity, viscous and thermal characteristic length) is fundamental for the acoustic optimization of the porous materials in the case of future applications.


Author(s):  
Paolo La Torraca ◽  
Luca Larcher ◽  
Paolo Lugli ◽  
Marco Bobinger ◽  
Francisco J. Romero ◽  
...  

1998 ◽  
Vol 264-268 ◽  
pp. 1201-1204
Author(s):  
F. Hamdani ◽  
M. Yeadon ◽  
David John Smith ◽  
H. Tang ◽  
W. Kim ◽  
...  
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