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2. Noise curve - Wikipedia

   en.wikipedia.org/wiki/Noise_curve

   Noise curves are a common way to characterise background noise in unoccupied buildings and spaces. [1] Their purpose is to produce a single-value representation of a complete sound spectrum. International standards organizations ( ISO , [ 2 ] ANSI [ 3 ] and ASA ) recognize the need to objectify judgements on the amount of ambient noise in ...

3. ITU-R 468 noise weighting - Wikipedia

   en.wikipedia.org/wiki/ITU-R_468_noise_weighting

   The human ear responds quite differently to clicks and bursts of random noise, and it is this difference that gave rise to the CCIR-468 weighting curve (now supported as an ITU standard), which together with quasi-peak measurement (rather than the rms measurement used with A-weighting) became widely used by broadcasters throughout Britain ...

4. Signal-to-noise ratio - Wikipedia

   en.wikipedia.org/wiki/Signal-to-noise_ratio

   If the noise has expected value of zero, as is common, the denominator is its variance, the square of its standard deviation σ N. The signal and the noise must be measured the same way, for example as voltages across the same impedance. Their root mean squares can alternatively be used according to:

5. Audio system measurements - Wikipedia

   en.wikipedia.org/wiki/Audio_system_measurements

   The measured curves for pure tones, for instance, are different from those for random noise. The ear also responds less well to short bursts, below 100 to 200 ms, than to continuous sounds [ 1 ] such that a quasi-peak detector has been found to give the most representative results when noise contains click or bursts, as is often the case for ...

6. Minimum detectable signal - Wikipedia

   en.wikipedia.org/wiki/Minimum_detectable_signal

   This required difference in power levels of the signal and the noise floor is known as the signal-to-noise ratio (SNR). To establish the minimum detectable signal (MDS) of a receiver we require several factors to be known. Required signal-to-noise ratio (SNR) Detection bandwidth (BW) Temperature T 0 of the receiver system; Receiver noise figure ...

7. Equal-loudness contour - Wikipedia

   en.wikipedia.org/wiki/Equal-loudness_contour

   The ITU-R 468 noise weighting curve, originally proposed in CCIR recommendation 468, but later adopted by numerous standards bodies (IEC, BSI, JIS, ITU) was based on the research, and incorporates a special quasi-peak detector to account for our reduced sensitivity to short bursts and clicks. [8]

8. Specific detectivity - Wikipedia

   en.wikipedia.org/wiki/Specific_detectivity

   Specific detectivity is given by =, where is the area of the photosensitive region of the detector, is the bandwidth, and NEP the noise equivalent power in units [W]. It is commonly expressed in Jones units ( c m ⋅ H z / W {\displaystyle cm\cdot {\sqrt {Hz}}/W} ) in honor of Robert Clark Jones who originally defined it.

9. Noise-equivalent power - Wikipedia

   en.wikipedia.org/wiki/Noise-equivalent_power

   Noise-equivalent power (NEP) is a measure of the sensitivity of a photodetector or detector system. It is defined as the signal power that gives a signal-to-noise ratio of one in a one hertz output bandwidth. [1] An output bandwidth of one hertz is equivalent to half a second of integration time. [2] The units of NEP are watts per square root ...