BS EN ISO 11904-1:2002 pdf download – Acoustics — Determination of sound immission from sound sources placed close to the ear — Part 1: Technique using a microphone in a real ear (MIRE technique).
1 Scope This part of ISO 1 1 904 specifies basic framework measurement methods for sound immission from sound sources placed close to the ear. These measurements are carried out with miniature or probe microphones inserted in the ear canals of human subjects. The measured values are subsequently converted into corresponding free-field or diffuse-field levels. The results are given as free-field related or diffuse-field related equivalent continuous A-weighted sound pressure levels. The technique is denoted the microphone-in-real-ear technique (MIRE technique). This part of ISO 1 1 904 is applicable to exposure from sources close to the ear, for example during equipment tests or at the workplace by earphones or hearing protectors with audio communication facilities. This part of ISO 1 1 904 is applicable in the frequency range from 20 Hz to 1 6 000 Hz. 2 Normative references m The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of ISO 1 1 904. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this part of ISO 1 1 904 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 8253-2:1992, Acoustics — Audiometric test methods — Part 2: Sound field audiometry with pure tone and narrow-band test signals IEC 60065, Audio, video and similar electronic apparatus — Safety requirements IEC 60268-7:1 996, Sound system equipment — Part 7: Headphones and earphones IEC 60601 -1 , Medical electrical equipment — Part 1: General requirements for safety IEC 60942, Electroacoustics — Sound calibrators IEC 61 094-1 , Measurement microphones — Part 1: Specifications for laboratory standard microphones IEC 61 260, Electroacoustics — Octave-band and fractional-octave-band filters IEC 61 672-1 , Electroacoustics — Sound level meters — Part 1: Specifications
3 Terms and definitions For the purposes of this part of ISO 1 1 904, the following terms and definitions apply. 3.1 ear canal measurement position position in the ear canal where the sound pressure is measured 3.2 ear canal sound pressure level L ear equivalent continuous sound pressure level measured at the ear canal measurement position NOTE When measured during exposure to sound under test, it is denoted L ear,exp . When optionally measured during exposure to a reference sound field in the determination of the free-field or diffuse-field frequency response according to clause 1 0, it is denoted L ear , FF or L ear,DF , respectively. When measured in one-third-octave frequency bands with nominal midband frequency f these are denoted L ear,exp,f , L ear,FF,f and L ear,DF,f . 3.3 human free-field frequency response ∆L FF,H,f difference, as a function of one-third-octave frequency bands f, between the sound pressure level at the ear canal measurement position with the subject exposed to a frontally incident plane sound wave, and the sound pressure level of the same sound field with the subject absent NOTE 1 The free-field frequency response is identical to the amplitude of the head-related transfer function (HRTF) for frontal sound incidence. NOTE 2 This definition is applicable to individual subjects and groups of subjects.
BS EN ISO 11904-1:2002 pdf download – Acoustics — Determination of sound immission from sound sources placed close to the ear — Part 1: Technique using a microphone in a real ear (MIRE technique)
