Sound Emitting Device for Selective Crowd Dispersal
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Solution Overview
Problem
Conventional methods for dispersing large gatherings of young individuals are often disruptive and confrontational, and existing sound dispersal devices affect all age groups equally, failing to specifically target younger persons effectively.
Innovation Solution
A sound emitting device that generates sound waves with frequencies in the range of 16.5kHz ± 1kHz, creating a ringing effect in younger persons' ears, while older individuals remain unaffected, using a combination of high and low frequency components with a beat frequency to create an unpleasant but non-harmful noise that encourages younger persons to move away.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional sound dispersal devices are used to disperse crowds, then all persons including older individuals are affected, but this causes disruption to the general public and can be confrontational
Solution Approach 1:
The patent applies local quality by using frequency-specific sound waves that target only certain age groups. The device emits ultrasonic frequencies (16.5kHz±1kHz) that are selectively perceived only by younger individuals with healthy hearing, while older persons are unaffected. This creates a localized effect on specific demographic groups without disrupting the general public.
2Adaptability or versatility
If high frequency sound waves (16.5kHz±1kHz) are used to target younger persons, then selectivity is improved, but the sound may cause discomfort or harm to those with sensitive hearing
Solution Approach 1:
The patent applies periodic action by using beat frequencies created through the interference of two closely spaced ultrasonic frequencies (16.5kHz±1kHz). This creates a periodic modulation effect that produces an unpleasant sensation in the ears of younger individuals, encouraging them to leave the area. The periodic nature of the beat frequency (typically 1-10Hz) creates a pulsating discomfort that is more effective than continuous tone.
3Reliability
If police intervention is used to disperse rowdy groups, then authority is asserted, but the situation becomes confrontational and disruptive
Solution Approach 1:
The patent replaces mechanical/police intervention with an acoustic field-based system. Instead of using physical force or authoritative presence to disperse crowds, the device uses inaudible to younger persons ultrasonic sound waves that create discomfort only for the target demographic. This substitution eliminates confrontation while maintaining dispersal reliability through selective acoustic targeting.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device effectively disperses young individuals from unsuitable locations without disturbing older persons, as the ringing sound is unpleasant for teenagers and encourages them to leave, while being safe and noticeable even through headphones or mobile phone use.
Implementation Method 1
sounding means for generating a sound wave in accordance with said signal
Implementation Method 2
mixing means for combining said first and second frequencies to create a high frequency component and a low frequency beat component
Data Source
Figure 1~2
AI summary
As shown in Figure 1, a sound emitting device (10) may be mounted to a wall near places which will be unsuitable for the congregation of young person, such as outside shops and on street corners. The device generates sound waves at a frequency that is detectable by one or more subgroups of individuals within a group of individuals.