| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem that it is not possible to sufficiently perceive environment constituted of a plurality of objects because it is not possible to determine distances to the objects in a device transmitting an ultrasonic wave and mixing the reflecting sound of the same with a local transmitting wave with a constant wavelength to convert the same to an audible sound up to now. <P>SOLUTION: A user can determine the distance to the objects because the frequency of an audible sound can be changed corresponding to the distances to the objects, and as a result the environment can be more precisely perceived, by transmitting an ultrasonic wave while increasing or decreasing frequency in a constant direction and by mixing the transmitted wave or the separately generated local transmitting wave and delayed reflected wave to convert the same to the audible sound. <P>COPYRIGHT: (C)2012,JPO&INPIT |
