General Description Of Noise Control Systems

A sound wave is a disturbance that repeats regularly in space and time and that transmits energy from one place to another with no transfer of matter. In Activity 2 on page 8 we had to model sound waves using an instrument. In our class we used a flute as the example and when the person blew into it, sound waves were produced. As they blew and changed the volume and pitch the sound waves changed. A sound wave is created when something vibrates. When something vibrates, longitudinal waves are created which we can hear. A longitudinal wave is a wave that transfers energy through compressions and rarefactions in the material that the wave travels which are all parts of a sound wave. In Activity 2 it states in some parts of the wave, the air molecules

The measuring cylinder was then used to accurately measure out 20 mL of water, which was then poured into the test tube that would be used for the experiment. The test tube was then placed into the clamp, which was then adjusted in order to make sure that the test tube was grasped firmly and would not fall out.

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.

In this experiment, the signal generator was set so that the frequency meter showed a reading of 1,803 Hz. The microphone was moved to a distance from the speaker so that the oscilloscope displayed a straight diagonal line. This position was of the microphone was recorded as the initial position, or beginning of a wavelength. The microphone was then moved farther in the same direction until the oscilloscope displays the same horizontal line. This position was recorded as final position, or the end of the wavelength. The distance between the two positions represents one wavelength for this frequency. This was repeated for frequencies of 2,402 Hz, 3,002, Hz, 3,602 Hz, and 4,201 Hz.

As the distance to an object is determined by measuring the time of flight and not by the intensity of the sound, ultrasonic sensors are excellent at suppressing background interference. Virtually all materials which reflect sound can be detected, regardless of their color. Even transparent materials or thin foils represent no problem for an ultrasonic

Sound waves are nothing more than an energy transfer through a medium be it through a liquid, solid, or a gas. Sound pressure or intensity is measured on logarithmic scale in decibels dB which increases on an order of magnitude. For instance a quiet conversation would be around 30 dB and whereas the human pain threshold would be just over 100 dB. While the pitch or frequency of the sound is measured in hertz or Hz, the higher the hertz the higher the pitch of the sound and vice versa (Hildebrand, 2004).

Namely, determining cable types and connectors, designing connection boxes and measuring required wire lengths are some of the major milestones completed during this phase. Determining the best cable type for the application is crucial for the accuracy of the measurement system. Several tests performed at NIST confirms that widely used Teflon cables, retains charge in the Tera-Ohm range resistance measurements. Therefore, for the measurement system developed, polyethylene cables were chosen to connect resistors and equipment. Furthermore, BPO (British Post Office) coaxial cable connectors were chosen as the connection method. Precision of cables and connectors are crucial for the measurement system developed. Therefore, additional testing were done to ensure the accuracy of the cables. Furthermore, the connectors were cleaned using an Ultra Sonic cleaner to remove oil and dirt that could affect the insulation. After cleaning the connectors, insulation between the terminals of the connectors was checked using the Tera-Ohm meter system at

Hospital noise is more than an annoyance. It disrupts patient sleep, creates spikes in blood pressure, and hinders wound healing and pain management. The post-partum unit at North Fulton Hospital has installed a traffic light device that reinforces awareness of the need for a quieter atmosphere by monitoring the noise level and turning from yellow to red as it rises. Even with this added device, noise consistently gets the worst marks on patient surveys. Noise-reduction efforts really gained momentum recently, when Medicare began basing a portion of hospital reimbursement on quality measurements including patient ratings of the quality of care (Landro, 2013). Additional measures need to be put in place in order to improve quality care by reducing distracting noises. White noise amplified through an intercom or machine will make the typical sounds become less obtrusive or obvious to the patient.

not apply to Richer Sounds as it is owned by only one person. They may

Closed-end air can be many things; ranging from brass instruments, woodwind instruments, organ pipes, and flutes. These closed-end air columns cannot produce an even harmonic. It has a 1st harmonic, 3rd harmonic, and fifth harmonic. These harmonics are can be understood as, the 2nd harmonic being twice that of the 1st, and the 4th being four times that of the 1st .

As a result of per the Building laws, the insulation is against airborne sounds like voices, not against the impact of sound against the walls like hammering a nail, noise pipes or vigour bed sheets. Once sound meets the building, like a floor, a ceiling or a wall the sound reflects back to the area, a part of it is absorbed by the fabric and the left over is transmitted to the succeeding area. The sound absorbed, mirrored and transmitted depends on each of the thickness/thinness of the wall as well as the material on the wall. (Figure 1)

The proposed Digital Line Array configuration will be ‘flown’; suspended 6+meters above ground. These DVA’s will be located on both sides of the stage. The 4 JSub Subwoofers will be equally spaced along the length of the stage, 2 Jsubs will sit atop the DVA, 2 will sit on the ground as to maximise the reach of the low frequency content.

The Local rack place at the same place with control surface and inside it is 2 Digital Signal Processing engine - Studer Score Live technology, with only 2 DSP cards will be capable of 64 inputs with 40-bit floating-point digital processor and one or multiple D21m I/O frames. The D21m high density I/O system holds up all the inputs and outputs to produce ultra-low noise balance mic amp and sends it to

Loudspeakers and Line Arrays play a vital role in live sound reinforcement. The main goal of line arrays is to evenly distribute the full range of frequencies and ‘loudness’ of the performance to the audience, no matter where the people are standing. Stage hands and audio technicians work together before a live performance in order to achieve the optimum sound quality for the audience’s satisfaction during their experience of the live event. Typically, traditional line arrays are set up by technicians on ground level. With the help of motorized hoists, the speakers are hanged or “flown” to be rigged at a specific height and achieve its J shaped curve- provided that the stage or venue is able to properly accommodate the speakers’ weight

The major acoustical issues in public buildings are concerned with the exclusion of outdoor noise and the separation of noise generated within the buildings. This chapter will consider specific types of public buildings in which acoustic designs are a matter of importance, such as schools, offices, libraries, recreational buildings, hospitals and government buildings. To obtain a space free from the annoyance of noise and excessive reverberation, a few step one could take would be as follows: planning the build with consideration of noise insulation so that rooms which contain sources of considerable noise level are separated from rooms that are required to silent; providing sufficient noise insulation for rooms where silence is need as well as implementing sound absorption to reduces the reverberation and noise created by that room to a more acceptable level. It is well to recognise that uncontrolled noise in public buildings will diminish their utility