Which combination will produce the lowest noise level?

To understand why the selection of the sequence at 74 dB with earplugs providing a Noise Reduction Rating (NRR) of 28 is the most effective combination for producing the lowest noise level, we can examine how dB levels and NRR work together.

The dB levels denote the sound pressure level generated by the MRI sequence, with lower values corresponding to quieter conditions. The NRR indicates how much sound exposure is reduced when earplugs are worn. To find the effective noise level (the estimated noise that a person experiences while wearing earplugs), you subtract the NRR from the dB level of the sequence.

In the case of the combination identified, the effective noise level is calculated as follows:

74 dB (sequence) - 28 NRR (earplugs) = 46 dB effective noise level.

Generalizing this approach for the other options shows that while some may have higher NRRs or lower dB levels, the combination of a relatively low dB level of 74 with an NRR of 28 strikes an optimal balance that leads to the lowest final sound exposure.

Higher dB sequences, even with high NRR earplugs, result in higher effective noise levels which can lead