ISO 11904-2:2021 pdf download – Acoustics — Determination of sound immission from sound sources placed close to the ear — Part 2: Technique using a manikin.
3.2 free-field? frequency? response? for? use? with? manikins ΔL FF,M,f average human free-field frequency response for use with manikins, corrected for the difference between the sound transmission inside the average human ear canal and the corresponding transmission of the manikin ear simulator Note 1 to entry: For applicability with manikins, the eardrum reference is replaced by the output of the manikin ear simulator in tabulated values of ΔL FF,M,f . Note 2 to entry: The free-field frequency response for use with manikins is identical to the amplitude of the head- related transfer function (HRTF) for frontal sound incidence. Note 3 to entry: The human free-field frequency response is defined in ISO 11904-1. 3.3 diffuse-field? frequency? response? for? use? with? manikins ΔL DF,M,f average human diffuse-field frequency response for use with manikins, corrected for the difference between the sound transmission inside the average human ear canal and the corresponding transmission of the manikin ear simulator Note 1 to entry: For applicability with manikins, the eardrum reference is replaced by the output of the manikin ear simulator in tabulated values of ΔL DF,M,f . Note 2 to entry: The human diffuse-field frequency response is defined in ISO 11904-1. 3.4 free-field? related? sound? pressure? level? determined? with? a? manikin L FF,M free-field sound pressure level determined with the method using a manikin Note 1 to entry: The definition may be applied to specific frequencies or frequency bands, weighted or unweighted levels, specific time weightings, etc., for instance “free-field related equivalent continuous A-weighted sound pressure level” (free-field related L M,Aeq , also denoted L FF,M,Aeq ). Note 2 to entry: The method is aimed at the mean free-field related sound pressure level that would be obtained with a large human population. Note 3 to entry: The free-field related sound pressure level for a human subject is defined in ISO 11904-1.