| 摘要 |
A new whistle which emits louder sound level with easiness of blowing air through the whistle. It direct the sound to intended subject by having sound opening area in front of the whistle to direct sound waves to go forward motion and it has capacity to change the insert able wound chamber and insert able sound chambers are attach able to each others. Also using a sound reflector and angled air tunnel on whistle with opening on top can be used to make sound waves go forward.
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