Non-Lethal Acoustical Weapons: Overview and Auditory ... · PDF fileNon-Lethal Acoustical Weapons: Overview and Auditory/Nonauditory ... • transducer’s diameter > wavelengths that

Ari GoldbergHUMAN FACTORS

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Non-Lethal Acoustical Weapons: Overview and Auditory/Nonauditory Risks*

Ari Goldberg, Ph.D. CandidateJohn G. Casali, Ph.D. CPE_____________________

Human Factors & Ergonomics CenterVirginia Tech

*Based on a review paper at Virginia Tech.

A reference listing is provided at the end of the slide set.


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Non-lethal Acoustical Weapons• Incapacitate while minimizing fatalities and permanent damage (JNLWD, n.d.)

• Purpose (DOD, n.d.)

• Peacekeeping• Humanitarian work• “Irregular warfare”

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Timeframe NamePast Weaponized microwave auditory effect

Mini explosion cannonsPresent Acoustic hailing devices

Underwater acoustic hailing devicesFlashbangs with multi‐launching devicesLA‐51 shotgun ammunitionMusic

Future Improved acoustic hailing devicesImproved underwater acoustic hailing devicesImproved flashbangs with multi launching devicesSubsurface non‐lethal engagement‐impulse swimmer gunOnes we may not know of yet (under development)

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Mob Excess Deterrent Using Silent Audio (MEDUSA)• Microwave Auditory Effect (MAE)• Incorporates Frequencies ≥ 5kHz• Sounds like “Spoken words within a person’s head” (Army, 1998)

• Used against enemy or to communicate with allies

• Risk of brain damage from stimuli greater than the ‘just‐perceptible levels’ (Hambling, 2008)

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PDT Agro Thunder Generator• Mini explosions; shockwave and noise (Hambling, 2010)

• Current: Bird control• Maximum Pulse Sequence: 2 Hz• 60‐100 shots/minute

• Proposed: Military and Police• Crowd control, defense installations, and hostage‐rescue operations (Opall‐Rome, 2010)

• Up to 170 dB (“From Bird Control,” n.d.)

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Figure 1. Thunder Generator (PDT Agro, n.d.)


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Acoustic Hailing Devices• Long range communication device

• Military and police• Produces an irritating or auditorially painful noise• Makes/models

• Long Range Acoustic Hailing Device (LRAD)• Max‐4• SoundCommander 5600• SHOPHAR Scream

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Long Range Acoustic Device (LRAD)

• Most well known• 2005 incident:

Seabourn Spirit cruise liner and Somali pirates (“I beat”, 2007)

• Featured on “Future Weapons”

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Figure 2. LRAD (“LRAD Corporation”, n.d.)


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LRAD: How it Works• Array of piezoelectric transducers (Wilson, n.d.)

• Sound level• Constructive interference (“Interference”, n.d.)**essentially, the opposite of phase cancellation in ANR headphones**

• Directionality (Wilson, n.d.)• Destructive interference• Size of the device

• transducer’s diameter > wavelengths that are output, keeps waves flatter with less dispersion to enable focus/aiming

• Frequency output: 1‐5 kHz

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LRAD Model Variants• LRAD 360X

• Emergencies and wildlife protection applications

• “Stacking dishes”

• LRAD 2000X• Maritime applications• Most powerful

• LRAD 100X• Crowd control • Portable

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Figure 3. LRAD 360X (“LRAD Corporation”, n.d.)


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dBA at 1 m

Beam width Range (m) for 80dBA

Coverage area (km) at 80dBA minimum

Highly intelligible speech minimum distance(m)

Max range of 88dBA over background noise (m)

360X x1 129 N/A 282 0.25 N/A N/A

360X x10

149 N/A 2,818 24.95 N/A N/A

2000X 162 ± 15° at 1 kHz/‐3dB

N/A N/A 8,900 N/A

100X 137 ± 15° at 2.5 kHz/‐3dB

N/A N/A 600 250

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Table 2. LRAD (“LRAD 360X”, n.d ; “LRAD 2000X” , n.d; “LRAD 100X”, n.d.)


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LRAD Risks• High dBA at midrange tones • Higher risk of noise‐induced hearing loss

• Operating frequencies in speech bandwidth

• 1 kHz• Auditory scotoma (hearing “blindspot”)

• Operators at risk, as well as targeted personnel

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Distance (m) SPL (dBA)

1 1622 1564 1508 14416 13832 13264 126128 120256 114

Table 3. LRAD 2000X


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Ultra Electronics HyperSpikeHyperShield• Riot shield for crowd control and riot control

• 2 kHZ• 140 dB SPL peak• Acoustic deterrent of 50m or greater

• 17 lbs.

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Figure 4. HyperShield (“HyperSpikeAcoustic”, n.d.)


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Underwater Acoustic Hailing Devices (UHAD)• Force protection and port security

• To combat swimmers and divers invading US waterways

• An area of longstanding research by the Naval Submarine Medical Research Lab in Groton, CT

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Figure 5. Combat swimmer (Navy Seals, 2013)


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eLOUD

(a UHAD)

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Figure 6. eLOUD (JNLWD, n.d.)


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eLOUD• 50% Sentence intelligibility up to 150 m• 150‐500m ambient noise issues (te Raa. L, Verhave J., DriessenF., Dreschler J., 2010)

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Bandwidth (Hz)

Maximum SPL at 2.7kHz at 1 meter (dB)

Maximum SPL at 500 Hz at 1 meter (dB)

Tones and voice messages up to (m)

Depth (m)

300‐5,000 190 180 457‐530 40

Table 4. eLOUD (Abraham, 2008; JNLWD, n.d.)


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SPLs at Threshold for Air and Underwater

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Figure 7. Sound pressure level thresholds for air and water. Adapted from “The effects of low frequency underwater sound on diver,” by S. J. Parvin, 1998, Proceedings of Undersea Defense Technology, pp227‐232.


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eLOUD Sound Pressure Levels (SPL)• Exact water attenuation and other effects are difficult to predict, due to function of:

• Depth• Temperature• Noise

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Distance (m) SPL (dB) at 500 Hz

SPL (dB) at 2.7kHz

1 180 1902 177 1874 174 1848 171 18116 168 17832 165 17564 162 172128 159 169256 156 166

Table 5. eLOUD SPL


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eLOUD SPLs and Effects

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Figure 8. SPL eLOUD 100. Adapted from “Bio‐effects of low frequency underwater sound (100 to 500 Hz),” by S. J. Parvin, 1998, Proceedings of Undersea Defense Technology, pp227‐232.


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eLOUD SPLs and Effects

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Figure 9. SPL eLOUD 500. Adapted from “Bio‐effects of low frequency underwater sound (500 to 2500 Hz),” by S. J. Parvin, 1998, Proceedings of Undersea Defense Technology, pp227‐232.


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References• Abraham B. (2008, October 25). eLOUD Enhanced Loudhailer [PDF document]. Retrieved from

www.aphysci.com/images/customer.../APS_eLOUD_Flysheet_Oct08.pdf

• Department of the Army. (1998, February 17). Bioeffects of Selected Nonlethal Weapons (fn1) (NGIC‐I 147‐101‐98 ) [PDF document]. Retrieved from www.freedomfchs.com/usarmyrptonmicrowavefx.pdf

• DoD Non Lethal Weapons Reference Book 2011. (n.d.). Scribd‐Joint Non‐Lethal Weapons Directorate (JNLWD). Retrieved May 2, 2013, from http://www.scribd.com/doc/112213696/DoD‐Non‐Lethal‐Weapons‐Reference‐Book‐2011‐pdf

• Enhanced Underwater Loudhailer ‐ U.S. Department of Defense Non‐Lethal Weapons Program. (n.d.). U.S. Department of Defense Non‐Lethal Weapons Program. Retrieved May 2, 2013, from http://jnlwp.defense.gov/current/ELoud.html

• From Bird Control to Riot Control (n.d.). PDT Agro. Retrieved February 22, 2014 from http://www.pdtagro.com/Non_Lethal_Weapon.html

• Hambling, D. (2008, July 6). The Microwave Scream Inside Your Skull . wired.com . Retrieved April 16, 2013, from http://www.wired.com/dangerroom/2008/07/the‐microwave‐s/

• Hambling, D. (2010, January 18). A Sonic Blaster So Loud, It Could Be Deadly | Danger Room | Wired.com. wired. Retrieved May 6, 2013, from http://www.wired.com/dangerroom/2010/01/a‐sonic‐blaster‐so‐loud‐it‐could‐be‐deadly/

• HyperSpike Acoustic Hailing Devices. (n.d.). Acoustic Hailing Devices. Retrieved April 17, 2013, from http://www.acoustichailingdevices.com/

• I beat pirates with a hose and sonic cannon. (2007, May 17). BBC News . Retrieved April 16, 2013, from http://news.bbc.co.uk/2/hi/uk_news/6664677.stm

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References• Interference and Beats. (n.d.). The Physics Classroom. Retrieved May 6, 2013, from

http://www.physicsclassroom.com/Class/sound/U11L3a.cfm

• "LRAD Corporation ‐Maritime." LRAD Corporation. N.p., n.d. Web. 6 May 2013. <http://www.lradx.com/site/content/view/287/110>.

• LRAD 100X. (n.d.). LRAD Corporation. Retrieved April 17, 2013, from http://www.lradx.com/site/content/view/207/110/



• Navy Seals (2013). Experience Diving Against Dolphins. Navy seals. Retrieved February 22, 2014, from http://navyseals.com/2210/a‐combat‐divers‐worst‐nightmare‐marine‐mammal‐program/

• Opall‐Rome, B. (2010, January 11). A Cannon 'Stun Gun' Israeli Device Harnesses Shock Waves for Homeland Defense. Defense News. Retrieved May 5, 2013, from http://www.defensenews.com/article/20100111/DEFFEAT01/1110306/A‐Cannon‐Stun‐Gun‐

• PDT Agro (n.d.). Thunder Generator Technical Features [PDF file]. Available from http://www.pdtagro.com/Bird_Control.html

• te Raa. L, Verhave J., Driessen F., Dreschler J. (2010, November). Experimental evaluation of a dedicated underwater loudhailer for diver warning. Paper presented at the Waterside Security Conference (WSS), 2010 International, The Hague, Netherlands.

• Wilson, T. (n.d.). How LRAD Works. HowStuffWorks. Retrieved April 16, 2013, from http://www.howstuffworks.com/lrad.htm

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ENGINEERING22Thank You! …Questions? 22

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Non-Lethal Acoustical Weapons: Overview and Auditory ... · PDF fileNon-Lethal Acoustical Weapons: Overview and Auditory/Nonauditory ... • transducer’s diameter > wavelengths that