The Use of Acoustic Quality Assessment in the Management of the Road Noise Reduction Project

The article presents a new approach to the tasks of noise assessment and reduction in the urbanized environment endangered by road noise sources. It was proposed to include the acoustic quality model in the currently applied quantitative noise assessment in the management of urbanized environment. In particular, this model takes into account subjective features of sound quality, i.e.： loudness, sharpness, roughness, and fluctuation strength as well as noise mmoya^ce assessment obtained in laboratory conditions. The proposed way can be used in estimating investment costs of an acoustic barrier at the design stage

LIGHTING QUALITY AND ACOUSTIC QUALITY IN LEED-CERTIFIED BUILDINGS USING OCCUPANT EVALUATION

Lighting quality and acoustic quality are often not well addressed in the current green building practice,including the Leadership in Energy and Environmental Design(LEED)Green Building Rating System in the US.While the level of LEED certification indicates the level of sustainability,it is not clear if a higher level of LEED certification also implies a more comfortable and productive work environment.The study intended to find the relationship between the level of LEED certification and the level of worker satisfaction and perceived job performance regarding lighting quality and acoustic quality from fifteen LEED-certified buildings.The findings indicate that the LEED Platinum building group tended to provide better lighting quality than the other lower certification groups,while the LEED Gold building group showed lower lighting quality and acoustic quality than the rest of the groups.Workplace designers and organizations should be mindful of the importance of lighting and acoustic qualities in promoting better comfort and productivity as it is easy to overlook these criteria when complying with LEED IEQ guidelines.

Evaluation of the Acoustic Environment in a Protestant Church Based on Measurements of Acoustic Descriptors

The new guidelines of the Catholic Church are in line with the guidelines adopted by Protestant churches since the Reformation, unifying appreciation for the liturgical practices of preaching and congregational singing. These guidelines require that the room, in this case the church, provides appropriate acoustic characteristics, which can be characterized by acoustic descriptors such as Reverberation Time (RT), Clarity (C80) and Definition (D50). In this article, we analyzed the acoustic quality of a protestant church whose design tried to follow these guidelines. Our findings revealed the poor quality of the acoustic environment in terms of both speech intelligibility and music. These findings emphasized the need to adopt not only Reverberation Time but also other acoustic descriptors such as Clarity and Definition in church design.

A PROPOSED LEED STANDARD FOR INDOOR ACOUSTICAL QUALITY

Acoustical quality of the indoor environment is increasingly being recognized as important in commercial, residentialand institutional building design. Unwanted sound is the most prevalent annoyance in many modern structures,leading to increased stress, loss of productivity and decreased quality of life for building occupants. The authors proposea minimum LEED standard for acoustical quality which can be incorporated into initial design or employed asa post-construction evaluation tool.

Mechanical quality factor of high-overtone bulk acoustic resonator

Mechanical quality factor Qm is a key characteristic parameter of High-overtone bulk acoustic resonator（HBAR）. The effects of structure parameter（thickness） and perfor？mance parameters（characteristic impedance and mechanical attenuation factor） of substrate,piezoelectric film and electrode constituting HBAR on Qm are carried out. The relationships between Qm and these parameters are obtained by a lumped parameter equivalent circuit instead of distributed parameter equivalent circuit near the resonance frequency, and the an？alytical expressions oi Qm are given. The results show that Qm increases non-monotonically with the continuous increase of the substrate thickness for HBAR with certain piezoelectric film thickness, and it approaches to the substrate material mechanical quality factor as the substrate thickness is large. Qm decreases wavily with the continuous increase of the piezoelectric film thickness for HBAR with certain substrate thickness. Sapphire and YAG with low mechanical loss are appropriate as the substrate to get a larger Qm- The electrode loss must be considered since it can reduce Qm- Compared with Au electrode, A1 electrode with lower loss can obtain higher Qm when the appropriate electrode thickness is selected. In addition, Qm decreases with the increase of frequency. These results provide the theoretical basis for optimizing the parameters of HBAR and show that trade-oflFs between Qm and must be considered in the design because their changes are often inconsistent.