Which characteristic does not determine the effect of noise on task p…

Which characteristic does not determine the effect of noise on task performance?

Answer & explanation

Correct answer: option 2

The correct answer is Option (2) → Luminance

Three characteristics of noise have been found to determine its effect on task performance: intensity, predictability and controllability.

Option (1) Intensity — Determines the effect (Incorrect). On a difficult task needing full concentration, intense noise lowers performance.

Option (2) Luminance — Does not determine the effect (Correct). Luminance is the brightness of light, a property of light and not of sound, so it is not a characteristic of noise at all.

Option (3) Predictability — Determines the effect (Incorrect). Noise that comes at intervals in an unpredictable way is more disturbing than noise that is continuously present.

Option (4) Controllability — Determines the effect (Incorrect). When tolerating or switching off the noise is within the person’s control, the number of errors in task performance decreases.

Note: The effects of noise on task performance are not there in the 2023-24 NCERT, which NTA followed in 2024, or in the NCERT book (2025-26); both books keep noise only as an example of an environmental stressor. They were there in the pre-rationalised NCERT, and hence this question has been picked from the pre-rationalised NCERT. Noise has gone quiet in the new book, yet it still made itself heard in this paper; the older book covers it in two short pages.

NCERT (2025-26): “Physical and Environmental Stress … Environmental stresses are aspects of our surroundings that are often unavoidable such as air pollution, crowding, noise, heat of the summer, winter cold, etc.…”

NCERT (Pre-rationalised): “Noise … Three characteristics of noise have been found to determine its effect on task performance, namely, intensity , predictability, and controllability of noise. Systematic research on the effects of noise on human beings shows the following :

When the task being performed is a simple mental task, such as addition of numbers, noise does not affect overall performance, whether it is loud or soft. In such situations, people adapt, or ‘get used’ to noise.
If the task being performed is very interesting, then, too, the presence of noise does not affect performance. This is because the nature of the task helps the individual to pay full attention to the task, and ignore the noise. This may also be one kind of adaptation.
When the noise comes at intervals, and in an unpredictable way, it is experienced as more disturbing than if the noise is continuously present. When the task being performed is difficult, or requires full concentration, then intense, unpredictable, and uncontrollable noise reduces the level of task performance.…”