GB2421655A

GB2421655A - High frequency sound teenager dispersal device

Info

Publication number: GB2421655A
Application number: GB0602284A
Authority: GB
Inventors: Howard Stapleton
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-08-23
Filing date: 2006-02-06
Publication date: 2006-06-28
Anticipated expiration: 2026-02-06
Also published as: GB2421655B; GB0602284D0; GB0517226D0

Abstract

A sound emitting device 10 generates sound waves using an oscillator 20 at a frequency that is detectable by one or more subgroups within a group of individuals, amplifies 30 this signal and emits it through a speaker 40. The device may use more than one oscillator operating at different frequencies and these may be combined in a mixer (50, figure 2) to provide a beat component in the emitted sound. A frequency above the perceptible range of most adults but audible to young people may be used, for example the frequency may be in the region of 16.5kHz. The beat frequency may be in the range of 1-10Hz. The device may emit sound over a limited angle, for example 50{-70{, allowing the signal to be directed to a particular area. The high pitched sound should be unpleasant to youths but outside the perceptible range of adults and is therefore expected to discourage the congregation of groups of teenagers near the device.

Description

Sound Emitting Device The present invention is concerned with the

generation of sound waves that are preferentially prominent to the hearing of young individuals, and Particularly but not exclusively to the generation of sound waves which are Preferentially prominent to the hearing of young individuals in order to disperse large gatherings of young individuals in a given location.

Sounds are characterised by their frequency and vary from the infrasonic vibrations (typically <20Hz) of earthquakes and volcanoes to the ultrasonic (typically >100kHz) calls of dolphins and bats.

Experiments have shown that a healthy young person hears all sound frequencies from approximately 20Hz to 20kHz. However, a person's lifestyle and age can reduce the sensitivity of the persons hearing, effectively reducing the audible frequency range. Elderly persons for example, typically cannot hear the upper range of frequencies. Accordingly, it is possible to target generally younger persons with sound waves which have a frequency in the upper quarter of the audible range, i.e. above 15kHz, since the majority of older persons will be incapable of detecting the sound.

The present invention is concerned with the dispersing of individuals and in particular groups of young persons in places where their congregation is unsuitable, such as outside shops and street corners. it is common for large numbers of young persons to gather at certain locations, which can jeopardise their own safety and which can often cause a hindrance to other members of the public. In addition, groups of rowdy young people can sometimes intimidate other passers-by. However, conventional methods of dispersing crowds of young people can often be disruptive to other members of the public and can be confrontatjonal, particularly if the police are required.

In accordance with the present invention, as seen from a first aspect there is provided a sound emitting device, said sound emitting device comprising oscillating means for generating a signal and sounding means for generating a sound wave in accordance with said signal, said sound wave having a frequency that is detectable by one or more subgroups of individuals within a group of individuals, wherein said one or more subgroups of individuals are caused to move away from said sound emitting device by said sound wave.

The frequency is chosen to be Preferentially unpleasant to younger persons. Operating the sound emitting device at lG.SkI-IZ+lkHz is found to create a ringing in the ears of young persons. Older persons typically cannot hear these higher frequencies and so are unaffected by the device.

Preferably, said sound emitting device generates a sound wave having a frequency of l6.5kHZ lkH, for example, l5.5kHz-l7.5k}jZ In accordance with this invention as seen from a second aspect, there is provided a Sound emitting device, said sound emitting device comprising oscillating means for generating a signal and sounding means for generating a Sound wave in accordance with said signal, wherein said signal causes said sounding means to generate a sound wave having a first frequency and a second frequency, said Sound wave being detectable by one or more Subgroups of individuals within a group of individuals.

Preferably, said device further comprises mixing means for combining said first and second frequencies to create a high frequency component and a low frequency beat component Preferably, said high frequency component is in the range l6.5kHz-i-kj It is well known that if two transducers are arranged to emit coherent sound waves of similar frequency, separately, the resulting superposition of the two waves will produce a so-called beat frequency. This beat frequency is simply the difference between the two driving frequencies of the transducers and creates a periodic surge in amplitude of the resulting sound wave.

Preferably, said low frequency beat component has a frequency in the range of 1-10Hz.

Preferably, said beat frequency is in the range of lHz-61-lz.

Preferably, said beat frequency is 3.8Hz 2Jj.

Preferably, said oscillating means varies the frequency of said signal between said first frequency and said second frequency.

Preferably, said sounding means comprises a transducer.

Preferably, said sounding means emits said Sound wave with an angular spread in direction in the range of substantially 500_700.

Preferably, said sound emitting device is mounted to a wall or post or similar.

Preferably, said Sound emitting device is hand-held.

Preferably, said sound emitting device has an operating range of substantially l5rn-20m.

Preferably, said subgroups of individuals are teenagers.

Preferably, said Sound emitting device is noticeable to those individuals whom are wearing headphones or using mobile phones.

In accordance with this invention as seen from a third aspect, there is provided a method of dispersing a group of individuals, said method comprising generating a signal to cause sounding means to generate a sound wave having a frequency detectable by one or more subgroups of individuals within said group of individuals.

The preferred embodiment of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which: Figure 1 is a schematic representation of the Sound emitting device in accordance with the first aspect of the invention; and, Figure 2 is a schematic representation of the sound emitting device in accordance with the second aspect of the invention.

Referring to figure 1, there is shown a Sound emitting device io. The device io comprises an oscillator 20, an amplifier 30 for increasing the signal received from the oscillator 20, and a transducer 40 for generating a sound wave at a frequency in the range of l6.5kHz lkHz, in accordance with the signal generated by the oscillator 20 and subsequently amplified by the amplifier 30. The device io may be mounted to a wall, near places which would be unsuitable for the congregation of young persons, such as outside shops or near street corners.

The device 10 is found to be Particularly effective over a range of 15m-20m with a directional spread of 50 - 70 . Moreover, the system is also found to have an effect on young persons wearing personal headphones or similar, while listening to music etc. The device 10 shown in figure 2 further comprises an additional oscillator 20 and a mixer 50 for combining the signal received from each oscillator 20. It is preferred that the signals from the two oscillators 20 generate signals which are of slightly different frequency, but each having a frequency within the range of l6.5kHz+lkHz.

In this manner the mixer 50 will generate a signal which will comprise a high frequency component in the range 16.5kHZ lkHZ, and a low beat frequency component of typically 1-10Hz but Preferably 3.8Hz 2Hz.

The use of a beat frequency is found to be more beneficial than a single monotone (i.e. single frequency) since in order for the device to work, the frequency must be (Preferentially) noticeable to the young persons.

However, it is found that unless there is a constant change or refreshing to a person's sense of hearing, the noise will not stay in a person's conscience and will therefore not act to repel the person from the location.

However, the beat frequency creates a slowly varying whining to the unpleasant high frequency component and therefore ensures that the noise is not biologically filtered from the persons conscience.

When large crowds of young persons gather near shops etc, the activation of the device causes a sound wave to be emitted of a particular frequency, which will be Preferentially noticeable to younger persons by virtue of their age. Furthermore, by emitting the Sound wave with a power of approximately 85db, which is less than the power level which causes permanent ear damage, it is found that the sound wave develops a ringing in the ears of the younger persons, and this development is found to occur regardless of whether they are wearing headphones or using a mobile phone. The ringing is Preferentially unpleasant to the younger persons and the slowly varying beat of the sound wave ensures that the noise remains a nuisance. Accordingly, the activation of the device results in the younger persons moving away from that location, while older persons remain oblivious to the sound.

Although wall mounted devices have been discussed, the device could be hand held and incorporated in a personal alarm. Alternatively, the device could be incorporated in a security system, such as an alarm system aimed at deterring intruders thereby providing an audible alarm that all can hear as well as an alarm that repels intruders that are sensitive to the Sound of the repeller device.

Claims

Claims 1. A sound emitting device, said sound emitting device comprising

oscillating means for generating a signal and sounding means for generating a sound wave in accordance with said signal, said Sound wave having a frequency that is detectable by one or more subgroups of individuals within a group of individuals, wherein said one or more subgroups of individuals are caused to move away from said sound emitting device by said sound wave.
2. A Sound emitting device as claimed in claim 1, wherein said high frequency component is in the range l6.5kHZ+lkH
3. A sound emitting device, said sound emitting device comprising oscillating means for generating a signal and sounding means for generating a sound wave in accordance with said signal, wherein said signal causes said sounding means to generate a sound wave having a first frequency and a second frequency, said sound wave being detectable by one or more subgroups of individuals within a group of individuals.
4. A sound emitting device as claimed in claim 3, wherein said device further comprises mixing means for combining said first and second frequencies to create a high frequency component and a low frequency beat component.
5. A Sound emitting device as claimed in claim 4, wherein said high frequency component is in the range 16. 5kHz lkHz
6. A Sound emitting device as claimed in claim 4, wherein Said low frequency beat component has a frequency in the range of 1-10Hz.
7. A Sound emitting device as claimed in claim 4, wherein Said low frequency beat component is in the range of l}jz-6Hz
8. A Sound emitting device as claimed in claim 4, wherein Said low frequency component is 3.8Hz 2J-i.
9. A Sound emitting device as claimed in claim 3, wherein said oscillating means varies the frequency of said signal between said first frequency and said second frequency.
10. A Sound emitting device as claimed in any Preceding claim, wherein said sounding means comprises a transducer.
11. A Sound emitting device as claimed in any preceding claim, wherein said sounding means emits said Sound wave with an angular spread in direction in the range of Substantially 50 -700.
12. A sound emitting device as claimed in any preceding claim, wherein said Sound emitting device is mounted to a wall or post or similar.
13. A Sound emitting device as claimed in any preceding claim, wherein said Sound emitting device is hand-held
14. A sound emitting device as claimed in any preceding claim, wherein said Sound emitting device has an operating range of substantially 15m- 20m.
15. A sound emitting device as claimed in any preceding claim, wherein said subgroups of individuals are teenagers.
16. A sound emitting device as claimed in any preceding claim, wherein said sound emitting device is noticeable to those individuals whom are wearing headphones or using mobile phones.
17. A method of dispersing a group of individuals, said method comprising generating a signal to cause sounding means to generate a sound wave having a frequency detectable by one or more subgroups of individuals Within said group of individuals.
18. A Sound emitting device substantially as herein described with reference to the accompanying drawings.