Which feature of the MAX engines contributes to reduced noise?

The feature of a higher bypass ratio in the MAX engines is crucial in reducing noise levels. A higher bypass ratio means that a larger portion of the air that passes through the engine does so without being burned in the combustion chamber. This results in quieter operation because the majority of the thrust is produced by the larger volume of air bypassing the engine core, rather than through high-speed exhaust gases that can generate significant noise.

In addition, this design allows for more efficient operation, as the engines produce less thrust-related noise while maintaining performance. The combination of reduced jet noise and fan noise significantly contributes to the overall noise reduction, making higher bypass ratio engines much quieter than those with lower ratios.

Other options, such as worn compressor blades or increased fuel flow, can actually lead to efficiency losses and increased noise rather than a reduction in noise levels. The use of titanium components is more about weight reduction and performance and does not have a direct impact on noise reduction. Thus, the advantage of a higher bypass ratio is clear in its role in quieter operation of the MAX engines.