HEARING APPARATUS Russian patent published in 1995 - IPC

FIELD: medical engineering, particularly, surdoengineering, hearing devices and devices for diagnosing weak sounds having intensity below threshold of physiological audibility. SUBSTANCE: object of this invention is increasing signal/noise ratio at output of hearing apparatus and correction of frequency characteristic by optimizing structural parameters of monotonously contracting matching round space inside hearing apparatus. Diameter of matching space output opening is equal to that of microphone inlet opening. Area of inlet opening, acoustic length of this space and angle of opening are optimizable structural parameters that can be selected with aid of formula presented in specification. Acoustic length of space is either equal or multiple to one forth of acoustic wave length in air at central frequency of region of correction of hearing apparatus frequency characteristic. EFFECT: increase in signal/noise ratio at hearing apparatus output, as compared with prior art miniature hearing apparatuses, allows distinguishing more weak sounds and extending sphere of application of such apparatuses. 5 dwg