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Noise measurement can also be part of a test procedure using white noise, or some other specialized form of test signal.In audio systems and broadcasting, specific methods are used to obtain subjectively valid results in order that different devices and signal paths may be compared regardless of the inconsistent spectral distribution and temporal properties of the noise that they generate.
A noise-figure meter could automate that procedure as follows: A gated broadband noise source (such as an avalanche diode) drives the device under test. A measurement is made with the noise source on; another measurement with the noise source off. From those measurements and the characteristics of the noise source, the noise figure can be ...
Analysis of sound and acoustics plays a role in such engineering tasks as product design, production test, machine performance, and process control. For instance, product design can require modification of sound level or noise for compliance with standards from ANSI, IEC, and ISO. The work might also involve design fine-tuning to meet market ...
A superball or power ball is a bouncy ball composed of a type of synthetic rubber (originally a hard elastomer polybutadiene alloy named Zectron) invented in 1964, which has a higher coefficient of restitution (0.92) than older balls such as the Spaldeen so that when dropped from a moderate height onto a level hard surface, it will bounce nearly all the way back up.
A noise or sound dose is the amount of sound a person is exposed to in a day. The dose is represented by a percentage. A noise dose of 100% means that a person has exceeded the permissible amount of noise. Any noise exposure after the 100% noise dose may damage hearing. The exchange rate is the rate at which exposure accumulates.
The toy is formed out of two solid balls of polymer, each about 2 inches (5 cm) in diameter, attached to a finger tab with a sturdy string. The player holds the tab with the balls hanging below and through up-and-down hand motion makes the two balls swing apart and back together, making the clacking noise that gives the toy its name.
The bounce of an oval-shaped ball (such as those used in gridiron football or rugby football) is in general much less predictable than the bounce of a spherical ball. Depending on the ball's alignment at impact, the normal force can act ahead or behind the centre of mass of the ball, and friction from the ground will depend on the alignment of ...
The core of the meter is based on a true RMS voltmeter, which measures the level of the noise signal. This was used for the first psophometers, in the 1930s. [2] As the human-perceived level of noise is more important for telephony than their raw voltage, a modern psophometer incorporates a weighting network to represent this perception.