IEC 61842:2002 pdf download

IEC 61842:2002 pdf download.Microphones and earphonesfor speech communications.
3.1.2
headset
assembly for speech communications, which consists of a holder to put on the talker’s head, one or two earphone parts and a microphone part, so as to keep the talker’s hands free
3.1.3
earset
assembly for speech communications, which consists of an earphone part and a microphone part, so as to keep the talker’s hands free, without a holder to put on the talker’s head
NOTE The distinction between an earset and a headset is as complicated as it is between an earphone and a headphone. Table 1 explains the definitions of earphone, headphone, earset and headset used in this standard.
3.1.4
microphone for speech communications:
a) part of a handset, an earset or a headset, which functions as a microphone (an acoustoelectrical transducer)
b) assembly of a microphone unit for speech communications and a case for measurement purposes, including acoustical circuit elements so as to obtain practical frequency characteristics
NOTE 1 A microphone for speech communications is understood to include devices, if any, such as amplifiers or impedance matching transformers up to the output terminals.
NOTE 2 A microphone for speech communications is called merely ‘microphone”, or “microphone part” of a handset, of an earset or of a headset, in Clause 4 of this standard and beyond.
3.1.5
earphone for speech communications
a) part of a handset, an earset or a headset, which functions as an earphone (an electroacoustic transducer)
b) assembly of an earphone unit for speech communications and a case for measurement purposes, including acoustical circuit elements so as to obtain practical frequency characteristics
NOTE 1 Any component which is intended by the manufacturer as an integral part of the earphone is included during measurements.
NOTE 2 An earphone for speech communications is called merely “earphone”, or “earphone part” of a handset, of an earset or of a headset, in Clause 4 of this standard and beyond.
3.1.6
microphone unit for speech communications
acousto-electrical transducer installed in a handset, in an earset or in a headset to pick up the talker’s speech in the vicinity of his/her mouth
NOTE The microphone unit for speech communications is called merely a “microphone unit” in Clause 4 of this standard and beyond.
3.1.7
earphone unit for speech communications
electroacoustic transducer installed in a handset, in an earset or in a headset to radiate sound signal in the vicinity of the listener’s ear
NOTE The earphone unit for speech communications is called merely an “earphone unit” in Clause 4 of this standard and beyond.
3.1.8
case for unit measurement
case in which a microphone unit or an earphone unit for speech communications is installed for measurement. It includes additional acoustic circuit elements so as to obtain practical frequency characteristics, if necessary
3.2.1
mouthpiece holes
holes bored into the front of the enclosure of a microphone unit for speech communications, to receive the in put sound
3.2.2
earcap holes
holes bored into the front of the enclosure of an earphone for speech communications, to radiate the output sound
3.2.3
artificial mouth
sound source for microphone measurement, which can produce the sound field similar to that around an ordinary human mouth
3.2.4
artificial ear
acoustic load for earphone measurement, whose acoustic impedance is similar to that of an ordinary human ear. It includes a microphone for measurement
3.2.5
lip ring
circular ring placed in front of the sound outlet of an artificial mouth for localizing the equivalent lip position
3.2.6
lip plane
outer plane of the lip ring, giving the reference point for finding the measuring position
3.2.7
external d.c. power supply
d.c. power supply for a microphone for speech communications including an amplifier or an electrical impedance converter circuit
3.2.8
additional resistance
electrical resistance for the earphone for speech communications which requires an external resistance for necessary adjustment of characteristics of the device
3.2.9
probe coil
coil for measurement of the external magnetic field of an earphone for speech communications
3.3 Characteristics and performance
3.3.1
sensitivity (VIPa).