EVS-ISO 7196:2002

This standard specifies a frequency-weighting characteristic, designated G, for the determination of weighted sound pressure levels of sound or noise whose spectrum lies partly or wholly within the frequency band from 1 Hz to 20 Hz.
NOTES
1  In the case of wide-band noises whose spectrum embraces both the infrasonic and audio-frequency ranges, use of this International Standard to determine the infrasonic weighted Sound pressure level is supplementary to the description of the same noise by methods already standardized which cover the audio-frequency range only, for example the description in terms of A-weighted sound pressure level. The numerical value of the results will, in general, differ from the G-weighted result. No significance should be attached to this difference since the respective results relate to different parts of the noise spectrum with little overlap.
2  The G-weighting can also be used in connection with the determination of sound power levels and sound intensity levels. When measured with the G-curve, these are symbolized respectively as LWG and LIG.