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PSYCHOPHYSICAL HEALTH IN RELATION TO THE ENVIRONMENTAL NOISE PERCEPTION IN YOUNGER VERSUS OLDER GROUPS OF PEOPLE IN DHAKA CITY

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Kazi Saifuddin

Corresponding author

 

Md. Shahinuzzaman, Noor Muhammad and Mohammad Abdul Quader1

Department of Geography and Environment, Jagannath University, Dhaka, Bangladesh

 

Abstract: Auditory perception towards environmental noise was tested individually in 510 graduate and undergraduate student participants  (18-28  yrs)  who  were  experienced  in  habitually  noisy-living  areas.  A  15-item  questionnaire  was  developed  to measure the auditory perception and the responses were evaluated by 10 teachers of Psychology living and working in Dhaka City. Another  33-item  ‘Burns  Anxiety  Inventory’  questionnaire  for  the  assessment  of psychophysical health  was  used  for the same participants. Results showed that increased level of negative perception towards environmental noise maintain a significant linear relation with the degradation of psychophysical health (P<0.01). Another study similar to the above one was performed in which  age factor  was  tested  as  a  parameter.  The  results  of  the  second  study  on  345  older participants  (55-65  yrs)  showed  a significant  improvement  of  psychophysical  health  (P<0.05), though  the  respondents  have  had  negative  perception  towards environmental noise. The inverse results of these two studies have been interpreted by assuming a threshold function (l) between the two age groups, where l represented a psychophysical antibody against the effects of environmental noise perception.

 

Key words: Psychophysical health, environmental noise perception, psychophysical antibody

 

Introduction

 

Noise  is  sound,  no  doubt,  but  it  can  specifically  be defined as the unwanted sound. It can also be explained mathematically   as   the   auditory   perception   of   the randomized-wave form of sound. In another way, noise has  been  defined  as  the  level  of  sound  which  exceeds the acceptable level and creates annoyance (Alam et al.2000).  The word noise  is derived from the Latin  word nausea meaning sickness. Noise is, however, among the most pervasive pollutant today. Everyday noises in the urban  areas  from  road  traffic,  jet  planes,  construction equipment and manufacturing processes, to name a few, are  the  unwanted  sounds  that  are  routinely  broadcast into  the  air,  and  these  have  been  called  environmental noise (Saifuddin et al. 2001, Saifuddin 2002a).

 

Dhaka is one of the biggest metropolitans and one of the most  polluted  cities  in  the  world.  Like air  and  water pollution, the inhabitants of this city are being exposed

to high levels of noise pollution (Ahmed 1998, Alam et al.  2000). The noise pollution  has  been  evaluated here on   the   basis   of   such   levels   that   correspond   to psychophysical  health  (Lundberg  and  Frankenhaeuser

1978,  Saifuddin  2002b).  Such  sound  levels  are  mostly dependent  on  the  intensity  and pressure.  The  intensity meaning  as  the  power-density  spectrum  is  the  average rate  of  sound energy  transmitted  through  a  unit  area perpendicular   to   the   direction   of   sound  propagation, typically measured in Pico-watts per square metre. Sound pressure  is  usually proportional  to  the  square  root  of sound  power.  Regarding  this,  a  logarithmic  measure called decibel  (dB)  is  used  to  describe  sound-pressure level. The A-weighted sound level, measured in decibel (dBA),  is  the  generally  accepted  scale  for  measuring sound level in highway transportation. However, studies on the acceptable  levels of noises during day  and night times in different areas of Dhaka City (Table 1) and noise levels at 37 roadside locations in Dhaka City during a 24- hr period (Table 2) reveal some interesting findings.

 

From  his  studies,  Ahmed  (1998)  established  a  linear relationship  between  the  noise  levels and  the  traffic volume   as   expressed   by   the   equation:   Sound   level (dBA)  =  43.818  + 0.0044TV;  (R2  =  0.98)  where,  TV denotes traffic volume in passenger car unit.

 

In a study conducted in Osaka City, Japan, the incidence of low-birth weight babies was found to be increased as the   noise   level   of   mother’s   living   area   increased, suggesting that such noise could be a possible cause of toxemia during pregnancy (Ando and Hattori 1974). In another   study  on   the   inhabitants   around   the   Osaka International  Air  Port,  Ando  and  Hattori  (1977) found that  the  human  placental  lactogen  levels  in  pregnant mothers after the 30th week  of pregnancy in  the noisy areas  tended  to  be  lower  than  those  in  the  reference areas.  Iwata (1984)  conducted  an  experiment  on  the relationship of noise sensitivity to health and personality,  and  he  noted  that  high  noise  sensitivity  is more  associated  with  mental  symptoms  than  physical ones.   In   subsequent   studies   (Ando   2000;   Saifuddin 2003) human auditory sensation has been designated as Description of Areas Day time Night time the  primary   auditory   sensation.   Keeping   the   above findings  in  mind,  here  an  attempt  has  been  made  to assess  the  psychophysical  health  (PH)  in  relation  to environmental  noise perception  in  two  age  groups  of subjects.  Then,  depending  on  the  results,  a  hypothesis has been  tested  in  which  human  auditory  perception towards  environmental  noise pollution  is  related  to  the psychophysical health. Therefore aim of this study was to  investigate  the  relationship  between  the  perceptual phenomena of the inhabitance towards the environmental  noise  and  their  psychophysical  health status. Noise perception as an individual   cognition towards the physical-environmental  exposure psychophysical   health   can   be   effected   individually through internal physiological correlates. The age factor as individualistic characteristics can also be a parameter between such perceptual process and the psychophysical health status. As it is well known that the age factor is the key determinant of perception as well as the health status to the age effects in this regard was another aim of this study.

 

 

Table 2. Roadside levels of noises (in dBA) in different areas of Dhaka City, measured during a 24 hr period (After Alam et al. 2000).

 

 

 

 

Materials and Methods

 

 

 

Participants:  Graduate  and  undergraduate  students  of both  sexes  (N=  510),  aged  between  18  and  28  years, took   part   in   the   study   as   younger   participants.   In addition, 345 professionals belonging to 55 to 65 years of  age  were  used  as  older  participants.  All  of  subjects were  selected  at  random,  sometimes  using  personal choices to those who were habitually living in the high-noisy  residential  areas  of  Dhaka  City.  The  participants were  interviewed  individually  without  any  formalities, but all of them were previously informed (prepared) for interview.  All  the  respondents  had  good  educational background,   they   were   all   conscious   about   noise pollution, and were of normal hearing.

 

Perception-measuring  questionnaire:  A  questionnaire written   in   Bengali   was   developed   to   assess   the

perception of the subjects towards noise pollution. A set

containing  25  questions  was  selected  primarily  by  the research  group  and  then  it  was  sent to  10  teachers  of Psychology  living  and  working  in  Dhaka  City.  The teachers  scrutinized  the questions  on  the  basis  of  their professional   experiences   and   judgments.   Thus,   the questions  were  re-evaluated  and  finally  15  questions (items) were chosen for the study. First 12 items in the set had the following four options for showing responses: 0 = not at all, 1 = a few, 2 = average and 3 = too much. Last three  items  in  the  set  contained  individually  three  and more  options  to  be  answered.  All  the  answers  were recorded by using tick mark (Ö) on the questionnaire.

 

Health-measuring questionnaire: Burns-Anxiety Inventory (BAI), devised by Burns (1990), was used to evaluate psychophysical health (PH) of the individuals. The BAI contains 33 items and four options (0, 1, 2, 3) to  answer  in  Bengali.  The  BAI  was  also  divided  into three  categories  in  which  Category  1  assessed  anxious feelings;  Category  2  assessed  anxious  thoughts;  and Category  3  assessed  physical  symptoms.  Total  scores recorded  for  each  individual  were  analyzed  using  BAI as shown in Table 3.

 

 

 

 

Procedures:  Younger  students  and  older  professionals  were selected through personal correspondence and were interviewed individually. The interviews took part either in the Department or in the residence of the participants. The subjects were explained primarily about the importance of the interview. The interviewers asked the subjects directly and provided specific marks according to the individual answers. The experimental data were   finally   scored   by   using   averaging   method   and   for determination test of significance were also used.

 

Results and Discussion

 

Noise perception in younger respondents: Results on the first study  (Table  4;  Fig.  1)  demonstrate that  increased  negative perception  (NP)  towards  noise  pollution  was  linearly  related (P<  0.01) to  psychophysical  health  degradation  (HD),  which could be shown by the equation: y » mx in which y, x and m indicate the HD, NP and a linear function, respectively.

 

 

Noise perception in older    respondents: Negative perception  towards  noise pollution  in  the second  study was found to have an inverse relation (P< 0.05) with the HD (Table 4; Fig. 2), meaning that if the perception is negative towards  noise, psychophysical health improved. Results  of  the  two  studies,  therefore,  are controversial owing only to differences in the age parameter of the respondents.

 

 

Conclusion

 

The  present  controversial  results  on  HD  in  terms  of environmental noise perception (NP) can be explained by an internal threshold mechanism which may be developed in between older and young age. The threshold mechanism (TM) might be accelerated by auditory-temporal perception, which is found from the significant experiment conducted  by  Saifuddin  (2001b).  The  TM  as  a  function achieved  by  experience  as  the  threshold  function  (l) which, can be controlled by hypothalamus of the brain in which, sympathetic and para-sympathetic   systems   are ivolved.If the individual has been living in environmentally noisy area for a long time, such TM can be developed. That is why,in spite of chronic environmental  noise,  the  psychophysical  health  might  be improved. The proposed threshold function, however, may be interpreted here as a psychophysical antibody to explain the observed controversy.

 

References

 

Ahmed K. 1998. A Study on Noise Pollution in Dhaka City. Directorate  of  Environment,  The  Government  of  the People’s Republic of Bangladesh.

Alam JB, Hoque MM and Ahmed MF. 2000. Traffic induced noise pollution  in Dhaka City. Bangladesh Environment 2000, 77-83.

Ando   Y.   2000.   A   theory   of   primary   sensations   and perceptions. J. Sound Vibration 241: 3-18.

Ando Y and Hattori H. 1974. Reaction of infants to air-craft noise  and  effects  of  the  noise  on human-fetal  life. Practica Otologica Kyoto 67: 129-136.

Ando  Y  and  Hattori  H.  1977.  Effects  of  noise  on  human- plancental  lactogen  levels  in  maternal  plasma. British J. Obstetrics Gynecol. 84: 115-118

Burns  DD.  1990.  Burns  Anxiety  Inventory.  Feeling  Good Handbook,  Plume,  North  Austin  (Last  modification: April 22, 2003).

Iwata  O.  1980.  Determinants  of  noise  effects.  In:  Noise  and Vibration Research Group of Environmental Sciences. Japanese   Ministry   of   Education   Grant-in-Aid   for Scientific Research.

Iwata O. 1984. The relationship of noise sensitivity to health and personality. Japanese Psychol. Res. 26(2): 75-81.

Lundberg  U  and  Frankenhaeuser  M.  1978.  Psycho-physiological reactions  to  noise  as  modified  by  personal  control  over noise intensity. Biol. Psychol. 6: 51-59.

Saifuddin   K.   2001.   Relationship   between   auditory-evoked potential  and  subjective  duration  in  respect  of  sound pressure level. Bangladesh Psychol. Studies 11: 69-76.

Saifuddin K. 2002a. Four dimensional standards of traffic noises in Dhaka City. Bangladesh Environment 1: 128-133.

Saifuddin   K.   2002b.   Differential   thresholds   of   subjective durations   of   bandpass   noises   and   complex   noises. Bangladesh Psychol. Studies 12: 37-42.

Saifuddin K. 2003. A theory of sensory dimension of auditory process. Bangladesh Psychol. Studies 13: 37-46.

Saifuddin K, Sakai H and Ando Y.  2001. Duration sensation of simulated    environmental    noise    in    relation    to    its autocorrelation function. J. Sound Vibration 241: 117-127.

 

Manuscript received on 21 December and revised on 17 January 2001.

 

Source: banglajol.info

 


 

 

 

 

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