Noise immission from sound sources close to the ear

With traditional measurement methods for noise exposure of humans (for e. g. assessment of work environment conditions), values are measured for the sound field, which the person is in is surrounded by. This is historically conditioned, because our reference material for hearing damages and annoyance is related to such values. When the sound source is close to the listener's ears as e. g. headphones, no surrounding sound field exists and such values can not be determined. Since it is still needful to relate the values for the situation with sources close to the ear to values for the surrounding sound field, it is required to determine the values of the surrounding field, which would have caused the same real ear exposure as the source close to the ear. In this project theoretical analyses of different measurement methods with miniature microphones in the ears of humans and with manikins have been made. Further, calculations of uncertainties for the different methods using measurements for different types of headphones have been made. Finally, data for correction procedures for the different methods have been collected and processed for the use in standardization (ISO 11904 and other, see project "Standardization"). Supported by STVF.