Acoustic Glossary


U : Sound and Vibration Definitions, Terms, Units, Measurements etc., ..

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Ultrasound Definition

IEC 801-21-04, acoustic oscillation whose frequency is above the high-frequency limit of audible sound (about 16 kHz)

Uncoupled Mode Definition

IEC 801-24-18, normal mode oscillating independently of other modes.

See also • Coupled Modes

Undamped Natural Frequency

the natural frequency of a structure.

Undamped Natural Frequency Definition

IEC 801-24-09, frequency of free oscillation resulting from only elastic and inertial forces of the system.

See also • Natural Frequency

Under-range the input to the sound level meter is too low for the current measurement range. Change the range.

Under-range % percentage of time an under range occurred

UnitsSI Units

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