During which circumstances is masking mainly applied in hearing tests?

Masking is primarily utilized during hearing tests when there is a risk of cross hearing. This situation arises when a sound presented to one ear can be heard by the other ear, potentially leading to inaccurate assessment of a person's hearing ability. Cross hearing can occur when there is a significant difference in hearing sensitivity between the ears or when the sound intensity is sufficiently loud to be transmitted through bone conduction.

By implementing masking, audiologists can prevent the non-test ear from participating in the test, ensuring that the results reflect the hearing ability of the test ear only. This is particularly crucial in accurate audiometric testing, as it provides a true representation of a patient's hearing capabilities without interference from the other ear.

The other circumstances listed do not necessitate masking. For instance, if noise levels are low, masking may not be needed since the background noise is not expected to interfere significantly with the test results. Similarly, masking is not limited to assessing the hearing of children; it is applicable across all age groups whenever the risk of cross hearing is present. Lastly, while assessing hearing aid effectiveness can involve various testing conditions, it typically does not specifically require masking unless cross hearing is a concern during the evaluation.