back-up beeper
{{Short description|Audible alarm when a vehicle is reversing}}
A back-up beeper, also known as back-up alarm or vehicle motion alarm, is a device intended to warn passers-by of a vehicle moving in reverse. Some models produce pure tone beeps at about 1000 Hz and 97-112 decibels.{{Cite journal |title=Vehicle Motion Alarms: Necessity, Noise Pollution, or Both? |last=Holzman |first=David C. |date=2011-01-01 |pages=A30–A33 |doi=10.1289/ehp.119-a30 |pmc=3018517 |pmid=21196143 |journal=Environmental Health Perspectives |volume=119|issue=1 }}
Matsusaburo Yamaguchi of Yamaguchi Electric Company, Japan, invented the back-up beeper which was first manufactured as model BA1 in 1963.{{cite web|url=http://www.triton-signal.com/index.php?option=com_content&view=article&id=27&Itemid=32 |title=Corporate Profile |publisher=Triton Signal USA |accessdate=February 11, 2012 |url-status=dead |archiveurl=https://web.archive.org/web/20111117093435/http://www.triton-signal.com/index.php?option=com_content&view=article&id=27&Itemid=32 |archivedate=November 17, 2011 }}
In the U.S., the back-up beeper was first manufactured by Ed Peterson who sold the system to Boise engineering firm Morrison Knudsen in 1967. As of 1999, the company marketed the Bac-A-Larm and sold about one million of the backup alarms annually, more than other suppliers.{{Cite news|url=https://www.nytimes.com/1999/05/29/business/ed-peterson-78-inventor-of-warning-alarm-for-trucks-backing-up.html|title=Ed Peterson, 78, Inventor of Warning Alarm for Trucks Backing up|newspaper=The New York Times|date=29 May 1999|last1=Ravo|first1=Nick}}
ISO 6165 describes "audible travel alarms", and ISO 9533 describes how to measure the performance of the alarms.{{Cite journal |last1=Popoff-Asotoff |first1=Peter |last2=Holgate |first2=Jonathan |last3=Macpherson |first3=John |date=21–23 November 2012 |title=Which is Safer – Tonal or Broadband Reversing Alarms? |url=https://www.acoustics.asn.au/conference_proceedings/AAS2012/papers/p126.pdf |journal=Proceedings of Acoustics 2012 - Fremantle |location=Fremantle, Australia}}
Criticism
File:Blackbird imitating the reverse signal of a truck.webm imitating the reverse signal of a local garbage truck]]
Back-up beepers have been criticized by the public and in scientific literature. Beepers are at or near the top of lists of complaints to government road builders about road construction noise. There is published concern that due to desensitization and the cry wolf effect people tend to disregard ever-present alarm sounds, diminishing their effectiveness.{{cite journal |last1=Bliss |first1=James P. |last2=Gilson |first2=Richard D. |last3=Deaton |first3=John E. |title=Human probability matching behaviour in response to alarms of varying reliability |journal=Ergonomics |date=27 March 2007 |volume=38 |issue=11 |pages=2300–2312 |doi=10.1080/00140139508925269 |pmid=7498189 |url=https://pubmed.ncbi.nlm.nih.gov/7498189/ |access-date=5 February 2021}} The typical 1000 Hz pure tone beeps at 97-112 decibels exceed the long-term hearing loss threshold of 70 decibels.{{Cite web|date=2019-10-07|title=What Noises Cause Hearing Loss? {{!}} NCEH {{!}} CDC|url=https://www.cdc.gov/nceh/hearing_loss/what_noises_cause_hearing_loss.html|access-date=2021-02-10|website=www.cdc.gov|language=en-us}}
Brains do not adapt to the repetitive and persistent sound of back-up beepers, but have evolved to process natural sounds that dissipate.{{Clarify|date=February 2021|reason=Prior paragraph contradicts this by saying that people become habituated.}} The sound is perceived as irritating or painful, which breaks concentration.{{cite news | url=http://www.rd.com/slideshows/everyday-things-that-drain-your-brain/ | title=Everyday Things that Make You Dumb: Why mundane experiences can throw your mental muscles for a loop | work=Reader's Digest | date=September 2012 | accessdate=October 28, 2012 | author=Wolchover, Natalie}}{{Better source needed|reason=Citation appears to be a simple news article list, with no source for this claim.|date=February 2021}}
In some countries, back-up warning systems using blasts of white noise have become more common. White noise is more audible than monotone beeping over background noise, and one can more easily ascertain the distance and direction of the sound.{{citation|title=Comparison of sound propagation and perception of three types of backup alarms with regards to worker safety|journal = Noise & Health|volume = 15|issue = 67|pages = 420–36|last1=Vaillancourt|first1=Véronique|last2=Nélisse|first2=Hugues|last3=Laroche|first3=Chantal|last4=Giguère|first4=Christian|last5=Boutin|first5=Jérôme|last6=Laferrière|first6=Pascal|date=Dec 2013|pmid = 24231421|doi = 10.4103/1463-1741.121249|doi-access=free}}
Regulations in the United States
Back-up beepers or an observer are required by OSHA for earth-moving vehicles with an obstructed view to the rear and no one on the ground to help guide the driver.{{ cite web | url=https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10769#1926.602(a)(9) | title=OSHA Material handling equipment 1926.602(a)(9) – Audible alarms | accessdate= 9 June 2016}} OSHA regulation 29 CFR Part 1926.601(b)(4) requires "a reverse signal alarm audible above surrounding noise level", but only when the motor vehicle has "an obstructed view to the rear". The determination of the noise level is left to the employer.
NHTSA requires electric vehicle warning sounds to alert pedestrians in electric and hybrid vehicles manufactured after 2018, for both forward and reverse travel at low speeds.{{cite web|title=Quiet Car Rule: New EVs Must Emit Warning Sounds In US By 2019|url=http://insideevs.com/quiet-car-rule-new-evs-must-emit-warning-sounds-us-2019/|publisher=Inside EVs|accessdate=2016-11-28}}