Human Factor Balance Under the Influence …
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The reaction force shows again a peak at second 3 when the sound occurred but
this time, the subject is unable to rebalance as fast as in case of sine waves and
unusual peaks continue to appear even after the sound stopped.
4 Conclusions
Based upon the experimental studies performed, the team found that the direction
the sound is coming from influences loss of stability in basically the same manner,
regardless of the sound direction. People have the tendency of getting away or “protecting” themselves from the noise especially when it is unexpected (they sway to the
front when the sound comes from the back, etc.). This might lead to loss of balance
and even fall, resulting in severe trauma or even death at certain workplaces.
It is known that frequencies affect the person’s balance in different ways but
if several harmonics are involved changing the wave shape, major influences are
witnessed. By comparing the types of sound waves, it was found that sawtooth
sound wave, which includes all harmonics, has the most powerful influence upon
losing stability. Of course, people react to sudden sounds at different extents, some
display minor loss of stability and some suffer significant changes of the stability
area. Also, after the first shock of surprise, their reaction is not so powerful if another
disturbing sound occurs a little later, the body being already alerted.
In order to avoid accidental falls due to occurrence of unexpected disturbing
sounds, people working in dangerous conditions might be checked following the
above procedure, thus identifying the persons who can be in danger at their workplace
and direct them to safer jobs or at least provide them with suitable safety equipment,
even if the noise is not permanent.
References
1. B. Smagowska, M.P. Luszczinska, Effects of ultrasonic noise on the human body—a bibliographic review. Int. J. Occup. Saf. Ergonomics 2(19), 195–202 (2013)
2. S.H. Park, K. Lee, T. Lockhart, S. Kim, Effects of sound on postural stability during quiet
standing. J. Neuroeng. Rehabil. 8(67) (2011)
3. H. Tamura, N. Ohgami, et al., Chronic exposure to low frequency noise at moderate levels causes
impaired balance in mice. PLOS ONE 7(6) (2012)
4. T. Tanaka, S. Kojima, H. Takeda, The influence of moving auditory stimuli on standing balance
in healthy young adults and the elderly. Ergonomics 44(15), 1403–1412 (2001)
5. B. Siedlecka, M. Sobera, A. Sikora, I. Drzewowska, The influence of sounds on posture control.
Acta of Bioengineering and Biomechanics 3(17), 95–102 (2015)
6. M.R.M. Mainenti, L.F. De Oliveira, T. De Melo et al., Stabilometric signal analysis in tests with
sound stimuli. Exp. Brain Res. 181, 229–236 (2007)
7. https://en.audiofanzine.com/getting-started/editorial/articles/in-search-of-the-perfect-wave.
html. Accessed July 2018
303
The reaction force shows again a peak at second 3 when the sound occurred but
this time, the subject is unable to rebalance as fast as in case of sine waves and
unusual peaks continue to appear even after the sound stopped.
4 Conclusions
Based upon the experimental studies performed, the team found that the direction
the sound is coming from influences loss of stability in basically the same manner,
regardless of the sound direction. People have the tendency of getting away or “protecting” themselves from the noise especially when it is unexpected (they sway to the
front when the sound comes from the back, etc.). This might lead to loss of balance
and even fall, resulting in severe trauma or even death at certain workplaces.
It is known that frequencies affect the person’s balance in different ways but
if several harmonics are involved changing the wave shape, major influences are
witnessed. By comparing the types of sound waves, it was found that sawtooth
sound wave, which includes all harmonics, has the most powerful influence upon
losing stability. Of course, people react to sudden sounds at different extents, some
display minor loss of stability and some suffer significant changes of the stability
area. Also, after the first shock of surprise, their reaction is not so powerful if another
disturbing sound occurs a little later, the body being already alerted.
In order to avoid accidental falls due to occurrence of unexpected disturbing
sounds, people working in dangerous conditions might be checked following the
above procedure, thus identifying the persons who can be in danger at their workplace
and direct them to safer jobs or at least provide them with suitable safety equipment,
even if the noise is not permanent.
References
1. B. Smagowska, M.P. Luszczinska, Effects of ultrasonic noise on the human body—a bibliographic review. Int. J. Occup. Saf. Ergonomics 2(19), 195–202 (2013)
2. S.H. Park, K. Lee, T. Lockhart, S. Kim, Effects of sound on postural stability during quiet
standing. J. Neuroeng. Rehabil. 8(67) (2011)
3. H. Tamura, N. Ohgami, et al., Chronic exposure to low frequency noise at moderate levels causes
impaired balance in mice. PLOS ONE 7(6) (2012)
4. T. Tanaka, S. Kojima, H. Takeda, The influence of moving auditory stimuli on standing balance
in healthy young adults and the elderly. Ergonomics 44(15), 1403–1412 (2001)
5. B. Siedlecka, M. Sobera, A. Sikora, I. Drzewowska, The influence of sounds on posture control.
Acta of Bioengineering and Biomechanics 3(17), 95–102 (2015)
6. M.R.M. Mainenti, L.F. De Oliveira, T. De Melo et al., Stabilometric signal analysis in tests with
sound stimuli. Exp. Brain Res. 181, 229–236 (2007)
7. https://en.audiofanzine.com/getting-started/editorial/articles/in-search-of-the-perfect-wave.
html. Accessed July 2018