Acoustics
Acoustics is the interdisciplinary science that deals with the study of sound, ultrasound and infrasound (all mechanical waves in gases, liquids, and solids). A scientist who works in the field of acoustics is an acoustician. The application of acoustics in technology is called acoustical engineering. There is often much overlap and interaction between the interests of acousticians and acoustical engineers.
Hearing is one of the most crucial means of survival in the animal world, and speech is one of the most distinctive characteristics of human development and culture. So it is no surprise that the science of acoustics spreads across so many facets of our society—music, medicine, architecture, industrial production, warfare and more. Art, craft, science and technology have provoked one another to advance the whole, as in many other fields of knowledge.
The word "acoustic" is derived from the Greek word ακουστικός (akoustikos), meaning "of or for hearing, ready to hear" and that from ακουστός (akoustos), "heard, audible", which in turn derives from the verb ακούω (akouo), "I hear". The Latin synonym is "sonic". After acousticians had extended their studies to frequencies above and below the audible range, it became conventional to identify these frequency ranges as "ultrasonic" and "infrasonic" respectively, while letting the word "acoustic" refer to the entire frequency range without limit.
Impact of Noise and Vibration on People and Products
By Daryoush Allaei (R&D, QRDC, Inc. Chaska, Minnesota, USA)
The effect of noise and vibration on people and products is an important issue for communities. In particular, the noise and vibration issues are more important when communities are around industrial facilities and transportation systems. There are a number of research groups throughout the world which have been actively researching these effects. The World Health Organization (WHO) is one of the well respected authorities. WHO defines health as “A state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity?” Even though this is a broad definition of health, it embraces the concept of well-being, and thereby renders noise impacts “health” issues. In general noise effects can be grouped into two broad categories: auditory (noise-induced hearing loss) and non-auditory (behavioral and physiological effects). Most products and machines not only are subjected to noise and vibration during their production, but also are the source or receiver of such dynamic forces during their operations. Therefore, the product quality and performance are also influenced by excess noise and vibration. This seminar focuses on an overview of the influence of noise and vibration on both people and products.
Impact of Noise and Vibration on People and Products
Comparison of sound environment between high and low density cities