| 摘要 |
To avoid the transmission errors frequently occurring in head-related two-channel transmission devices - inversion of direction, in-head localisation, elevation, sound distortion, lack of loudspeaker compatibility and audible internal noise - a new wide band low-noise artificial-head pick-up system having a wide dynamic range has been developed, the external geometry of which is built up with accurate consideration of the structure-averaged direction-dependent parameters which are acoustically active in a person and is provided with two high-quality microphones with a calibration capability usual in measuring techniques, which, due to small dimensions which allows a wide band utilisation of the simulation of the external ear as a passive acoustical amplifier, low internal noise and wide dynamic range, bring about an improvement in the electro-acoustical transmission characteristics and, by means of an active filter, ensures a frequency response of the microphone transfer functions which, when irradiated with free-field sound from the front is comparable to a measuring microphone so that this system, on the one hand, provides the possibility of analysing sound events by measuring techniques as usual in acoustical measuring technology and, in addition, generates during the reproduction via free-field-equalised headphones, the same sound pressure signals at the eardrums of a listening person as if the person were located at the location of the sound pick-up and, on the other hand, no interfering sound distortion occurs during the reproduction via loudspeakers. The entire artificial-head system is designed for mains and also battery operation and is combined with an analog or digital recording device to form an autonomous recording and replay system.
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