| 摘要 |
PROBLEM TO BE SOLVED: To provide a bird and beast-repelling apparatus whose threat signals are hardly leaned by birds and beasts and which can prevent the birds and beasts from approaching a desired region or repel the birds and beasts. SOLUTION: This bird and beast-repelling apparatus is characterized by having a means for automatically changing sounds several times, when sounds cycles each comprising continuously emitting two or more kinds of the sounds and then not emitting the sound for a constant time are repeated several times, and then further repeated constant times, while changing the sounds. Thus, the emission forms of the various threat signals are complicated. COPYRIGHT: (C)2004,JPO
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