When a task requires the use of auditory signals, speech or nonspeech, noise at any level sufficient to mask or interfere with the perception of these signals interferes with the performance of the task.
Where mental or motor tasks do not involve auditory signals, the effects of noise on their performance are difficult to assess. Human behavior is complicated, and discovering how different kinds of noises influence different kinds of people doing different kinds of tasks is difficult. Nonetheless, the following general conclusions have emerged. Steady noises without special meaning do not seem to interfere with human performance unless the A-weighted noise level exceeds about 90 dBs. Irregular bursts of noise (intrusive noise) are more disruptive than steady noises. Even when the A-weighted sound levels of irregular bursts are below 90 dBs, they can interfere with the performance of a task. High-frequency components of noise, above about 1000-2000 Hz, produce more interference with performance than low-frequency components of noise.
Noise does not seem to influence the overall rate of work, but high levels of noise can increase the variability of the rate of work. Noise pauses followed by compensating increases in the work rate can occur. Noise is more likely to reduce the accuracy of work than to reduce the total quantity of work. Complex tasks are more likely to be adversely influenced by noise than are simple tasks.
Was this article helpful?