Noise characterisation is a critical research area for varied domains and applications. The domains

It is better to put a soundproof enclosure around a noisy machine than to expect everyone who might be exposed to the machine's noise to wear hearing protection for example compressors.

Noise pollution cannot be fully eliminated but as stated before, it can be reduced to an acceptable level. Effects of noise varies greatly depending on the types of source, location of the recipient and the time of production. Hence, the noise produced by the aviation industry and its related operations are mitigated by different techniques and methods, which are as follows.

As newer research began during the 1900s, the sonar started to make changes and new developments. Active sonar, provides pulses of sounds and listening for echoes. Gives warning if an object is in the path and returns an “echo” to the sonar transducer. The transducer can determine the range and orientation of the object. Passive sonar systems are used primarily to detect noise from marine objects (such as submarines or ships). Unlike active sonar, passive sonar does not emit its own signal, which is an advantage for military vessels that do not want to be found or for scientific missions that concentrate on quietly “listening” to the ocean. The purpose for both sonar’s is to detect the acoustic signals emanating from external

This is increasingly prevalent as our cities become ever more densely populated and built-up. To try and reduce this disruption and isolate the sound inside or out of different spaces, acoustic insulation can be used – often labelled soundproofing. There are several different types, each with the common aim to decrease the sound pressure level in certain different spaces. Many techniques, such as damping, reflection, diffusion and cancellation, can all be used to achieve this.

To "Parrot Zik" is equipped with active noise cancellation function to cancel 98% maximum external noise. Actually on the train, including the subway, classical, jazz, rock, pop, but try to check listening to all music genres, such as techno, the sound of the motor and the wheels is reduced, you can enjoy the pleasant music I was able to.

For getting rid of all unwanted noises across the United States, and for making a better and peaceful America.

Because noise is a result of sound and sound has the potential to be noise; a nuisance if a sound becomes noise or a pleasure as long as it remains a sound. If it is harmful to health of man or beast then it is always ‘unwanted sound’. It may be unwanted noise but it may well be necessary noise, for example industrial noise and it is also the noise of modern progress, as Gareet Keizer puts it in the title of his book, it is the “Unwanted Sound Of Everything We

Acoustic waves are an isolation of pressure that travel in a wave pattern. Acoustic waves cause a vibration that leads to your ear that allows us to hear. These acoustic waves are defined by three different characteristics. These characteristics are amplitude, frequency and wave length. Amplitude is the energy in a wave. The amplitude affects its volume or sound. The number of waves that pass a point at each second, the higher the frequency, the higher the pitch compared to those who have low frequencies. You can describe these waves as the waves that allow humans and other species to hear.

A range of observations were conducted to assess acoustic spaces in terms of their characteristics and ambient noise levels. Using a Digitech QM 1589 (see figure one) three studies were measured in order to successfully account for characteristic behaviours and differentiate between ambient noise levels. These studies where assessed under A and C weightings and in fast and slow settings. A weighting follows the frequency sensitivity of the human ear at low

There are some negative effects of sound and that is what we call noise. As William H. Stewart (2002) states “calling noise a nuisance is like calling smog an inconvenience”. Noise is the television not working and workers drilling in the morning. It’s when neighbors play music too loudly,

The length and diameter of a PVC pipe were measured. These measurement are recorded in table 1. The system was programmed to start data collection the moment the noise level is 0.2 above the background noise. Then, the PVC pipe was held perpendicular to the microphone

As an aside, our friends who are focusing their studies on the exciting future of ‘Sound’, need not be disheartened since even after this innovation comes around,’ Sound’ shall continue to exist all around us, except within us, and that too, only when we would want it to be so. I am sure even they themselves would greatly benefit from this innovation.

In last months, my centre of attention was on understanding the qualification of atmosphere factors perturbation in sound speed and comparing different acoustic tomography methods. Then, these techniques have been applied to series of synthetic and obtained data from field trials.

where Z0 and Z1 are the acoustic impedances of the first and second medium, respectively, although this simple relation cannot be utilized in case of abnormal incidents, due to interchange conversion between P-waves and S-waves, and can be described by Zoeppritz equations, where the amplitudes of reflected and refracted waves at a planar interface for an incident P-wave as a function of the

Every wonder why construction workers, Djs, Sound guys, Night club workers wear protective ear wear? Long term exposures to the amplitude of certain sounds at certain levels can cause very real deafness. Acoustics can also be used to levitate very light objects, but it could only be a matter of time before we could use acoustics to move heavy objects with the right amount of power.