Frequency is measured in hertz (Hz). For sound, this means the number of pressure waves per second that would move past a fixed point. It is also the same as the number of vibrations per second the particles are making as they transmit the sound. A sound of 10Hz means that 10 waves would pass a fixed point in 1 second.

Which is the best description of a sound wave when the pitch of the sound is very high? It has a low frequency.

Sound is a mechanical wave that results from the back and forth vibration of the particles of the medium through which the sound wave is moving. The motion of the particles is parallel (and anti-parallel) to the direction of the energy transport. This is what characterizes sound waves in air as longitudinal waves.

80 dB

The most common instruments used for measuring noise are the sound level meter (SLM), the integrating sound level meter (ISLM), and the noise dosimeter. It is important that you understand the calibration, operation and reading the instrument you use.

A sound level of 0 dB is approximately the threshold of human hearing and is barely audible under extremely quiet listening conditions. Normal speech has a sound level of approximately 60 dB; sound levels above 120 dB begin to be felt inside the human ear as discomfort.

Put simply, a noise dosimeter is a specialised type of sound level meter that is used to measure personal noise exposure levels. They can also be used when it isn’t safe or practical to use a full-sized sound level meter, such as in areas with a high fire risk or in confined spaces.

Decibel (dB), unit for expressing the ratio between two physical quantities, usually amounts of acoustic or electric power, or for measuring the relative loudness of sounds. One decibel (0.1 bel) equals 10 times the common logarithm of the power ratio.

A-weighted decibels, abbreviated dBA, or dBa, or dB(a), are an expression of the relative loudness of sounds in air as perceived by the human ear. In computer systems, dBA is often used to specify the loudness of the fan used to cool the microprocessor and associated components.

Sound Pressure Level Calculator SPL (dB) = 10 log10(p2/po2). Sound pressure p in Pa & reference sound pressure level po in Pa are the key elements of this calculation. It’s useful tool to find out the audible sound or noise pollution.

In common usage, decibels are usually a way to measure the volume (loudness) of a sound. Decibels are a base 10 logarithmic unit, which means that increasing a sound by 10 decibels results in a sound that is twice as loud as the “base” sound.

The answer is, “Yes,” but only four apps that were tested measure up. The National Institute for Occupational Safety and Health (NIOSH) evaluated the apps at its acoustic testing lab. The tests also compared results for i-Phones and Android phones. No Windows phone noise apps met NIOSH’s standards either.

The Krakatoa volcanic eruption: Not only did it cause serious damage to the island, the eruption of Krakatoa in 1883 created the loudest sound ever reported at 180 dB. It was so loud it was heard 3,000 miles (5,000 km) away.