Noise stress tests are also carried out to demonstrate the robustness and effectiveness of the FD-based index for damage localization with different stiffness losses and SNR values.

But recent studies suggest that noise could even be dangerous, increasing stress levels and risk of illness - the word "noise" does derive from the Latin "nausea" after all.

But among the many studies that evaluated death from heart problems, some did not separate stress and noise from air pollution as a cause, it said.