Iran Occupational Health

 The influences of Low Frequency Noise (LFN) on mental performance have been the objectives of many papers in recent years. Many researchers believe that the LFN even at low pressure levels has impacts on mental performance. In the present work the influences of LFN and Reference Noise (RN) at two different sound pressure levels (45 & 65 dBA) on mental performances of college students during solving math problems were studied. Other factors such as annoyance and sensitivity to LFN and hearing status of the participants were also determined.

  Material and Methods

Low Frequency and Reference Noise were generated and verified using Cool Edit software program. The number of participants was calculated using data gathered from a pilot study conducted in advance. The mental performance of the students was evaluated while they were exposed to LFN and RN at 45 & 65 dBA sound pressure levels. For this purpose, standard psychological tests were applied. Standard measuring instrumentation including sound level meters, psychological tests, acoustic room and etc were calibrated prior to their application based on standard methods.

  Results

 The results revealed that, Low frequency noise annoyance and sensitivity have no significant differences between different studied ages and sexes. The results also revealed that, a significant correlations exists between sensitivity to low frequency noise and deep mental process (r=0.33, p=0.01). It was recognized that low frequency noise at 65 dBA can decrease accuracy (p_value=0.005) and performance (p_value=0.001) in comparison with reference noise at the same level.

  Conclusion

 Low frequency noise, have impact on mental performance during performing math calculations