“ISO 31-7”的意思、由来-开放百科全书

词条

ISO 31-7

释义

ISO 31-7 is the part of international standard ISO 31 that defines names and symbols for quantities and units related to acoustics. It is superseded by ISO 80000-8.

Its definitions include:

Quantity			Unit		Remarks
Name	Symbol	Definition	Name	Symbol	Remarks
period, periodic time	T	time of one cycle	second	s
frequency	f, ν	f = 1/T	hertz	Hz	1 Hz = 1 s⁻¹
. . .
loudness level	L_N	L_N = ln(p_eff/p₀)_1 kHz where p_eff is the root-mean-square value of the sound pressure of a pure tone of 1 kHz, which is judged by a normal observer under standardized listening conditions as being as loud as the sound under investigation, and where p₀ = 20 µPa	phon	The loudness level is 1 phon if 20 log₁₀(p_eff/p₀)_1 kHz=1, that is for a pure tone of frequency 1 kHz, 1 phon = 1 dB sound pressure level. This is not a purely physical quantity and unit, as it involves the subjective evaluation by humans.
loudness	N	A normal observer's auditory estimate of the ratio between the strength of the sound considered and that of a reference sound having a loudness level of 40 phons	sone	A standard relation between loudness in sones and loudness level in phons has been adopted for practical use in ISO 131.

2 : Acoustics|ISO 31

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