A Sound Quality Study of Household Electrical Appliances by Jury Test in Indoor Space

Abstract

This paper establishes a procedure for the evaluation of human hearing perception in indoor spaces by jury testing. An artificial head system was used to record indoor noise and to determine physical acoustic and psychoacoustic parameters within living and working environments. This test involved a jury consisting of 102 people of different ages, genders and occupations. The subjects participated in the sound quality evaluation and from this; indicators of human perception to sound were obtained.Three types of residential spaces in which to carry out the jury test were selected, including a high-rise apartment, a general residential apartment and a small apartment suite. A workspace in the form of a medium-sized meeting room was also tested. The paired comparison method and the category judgment method were both utilized in the jury test questionnaire. The paired comparison method was used to evaluate the psychoacoustic perception of loudness and sharpness, while the category judgment method applied a seven-point scale. Psychoacoustic parameters were used to analyze human hearing responses; from these, perceived sound quality was established for each subject. Through this testing procedure, a reasonable sound quality evaluation method was established. © Chang et al.; Licensee Bentham Open. This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.

Numerical Analysis of Indoor Sound Quality Evaluation Using Finite Element Method

“…where { } is the displacement vector of the structure on the interface and 0 is the fluid density. Substituting (6) into 5, it shows…”

“…Chiang et al [5] analyzed the impulse responses measured in three theater types using Hyper Signal to measure the physical parameters of acoustic competence and compared how enclosure affected that acoustic competence. Chang et al [6] used the jury testing to establish an evaluation procedure for human hearing perception in indoor space. They carried out this testing in three types of residential spaces and built a reasonable sound quality assessment method.…”

Harvesting acoustic energy by coherence resonance of a bi-stable piezoelectric harvester

“…Acoustic noise as a clear, ubiquitous and renewable energy is prevalent abundantly both in domestic and industrial environments. Chang et al [12] indicated that the sound pressure level (SPL) in the surroundings of household appliances (hair dryer, juicer, vacuum cleaner, and bean grinder) ranges from 67 dB to 78 dB, while the SPL of acoustic noise ranges from 87.7 dB to 136 dB in the environment of industries (print industry, textile manufacturing industry, fiber glass industry, etc.) [13,14].…”

An improved design of Helmholtz resonator for acoustic energy harvesting devices

“…Converting ambient acoustical noise with an acoustic energy harvester into a useful electrical power is most appropriate for enhancing the lifecycle of batteries used in WSNs. Conversation 65 [9] Train Station 100 [9] Jet aircraft at takeoff 130 [9] Shaver 56 [10] Extractor hood 69 [10] Grinder 72 [10] Binding machines 85.6 [11] Printing presses 86 [11] Cutters 90.8 [11] Paper perforating 88.9 [11] Turbofan engines 150 [12] Automobile surrounding 90 [13] In acoustic energy harvesting devices a HR is incorporated with an energy transformation technique like piezoelectricity where piezoelectric materials are used or electromagnetism where coil and magnets are used. HR is used to augment or attenuate the acoustic wave objective of HR in acoustic energy harvesti augment the incoming acoustic wave.…”