The Airbus A380 is considered to have the quietest long-haul cabin in the skies. The study notes that "ircraft noise has been significantly reduced by evolution of noise-reducing engine technology (e.g., Pratt and Whitney PurePower Geared TurboFan engine reduces noise footprint by 75%) combined and with the introduction of newer aircraft models and airframes with a lower noise profile (e.g., Boeing 787 and Airbus A380)." I turned to other sources to see if decibel levels were recorded or released. All of them mount newer and much quieter engines than the previous generation.
PASSENGER BAND DECIBELS SERIES
It didn't include either the newest single-aisle jets, the Airbus A220 and A320neo series and the Boeing 737 MAX. Unfortunately, the study did not include several long-haul leaders, such as the Boeing 747, the Boeing 787 Dreamliner, the Airbus A350 or the Airbus A380. Similarly, the 737 is 0.9 decibels louder than the A320, or about 10% "louder". However, because of the logarithmic scale used in reporting decibels, this means the Boeing is about 50% "louder" than the Embraer aircraft. The decibel levels do not differ dramatically between aircraft: the loudest aircraft, the Boeing 737, is 4.9 decibels louder than the Embraer regional jet. The inside of an aircraft during flight? About 80 decibels, or about four times as loud as the typical office. With that in mind, absolute silence is zero decibels. Similarly, every increase of 10 decibels represents a 10X increase in the intensity of the sound - but critically, a 2X factor of the perceived "loudness" (which is a subjective measure). A 7.0 magnitude earthquake differs dramatically in terms of destruction from a 5.5 on the Richter scale. The Decibel: How Sound Is Measuredĭecibels are measured on a logarithmic scale, not a linear scale, similar to the Richter scale for seismic activity. Geared turbofans can be found most commonly on the Airbus A220 and A320neo series, and on the Boeing 737 MAX.
Thanks to a gearbox between the fan at the front of the engine and the compressor behind it, the fan can be slowed down - which makes it quieter, since fan blade tips approaching the speed of sound make a special kind of whine.
In addition, the advent of geared turbofan engines has resulted in quieter engines. The engines on most jet aircraft you will fly on these days are almost all of the high-bypass variety.
Engines with high bypass ratios (the ratio of air bypassing the engine core to that flowing through the core) results in lower exhaust speed and thus less noise. The FAA has mandated that aircraft designed after Janumust be compliant with new, quieter decibel restrictions. The good news is that the noise levels are decreasing, forced by regulation and steady improvements in engine and aircraft design. Surprisingly, Canadian researchers found that "high speed turbulent flow over an aircraft fuselage is responsible for a substantial component of the interior noise, and is probably the most important source of cabin noise for jet powered passenger aircraft in steady cruise." It's the plane itself moving through the air delivering most of the cabin noise, and not simply the engines. However, in-flight noise also results from airflow around surfaces such as wings, flaps and landing gear. Passengers intuitively know that the engines are the main source of aircraft noise. So, which aircraft are the quietest aloft? And where should you aim to sit on board? First, What's Causing the Noise? On the Air France flight, had I been sitting on the lower deck in economy, behind the engines, it would not have seemed quite so quiet. The truth is my ears perceive the Q400 to be about twice as loud as the A380.Ī 2018 study published in the Journal of Exposure Science & Environmental Epidemiology points the way: how loud you perceive the cabin noise to be depends on the aircraft, and where you sit on board. The "Q" of the Q400 is supposed to stand for quiet a noise-cancelling system is built in.
There was a dull roar during taxiing and that roar increased to a visceral, low, rapid thumping as the second engine was started and the plane throttled up. The second flight was aboard a Bombardier Q400 turboprop aircraft from Newark to Halifax, Nova Scotia. Of course - lucky me! - I was firmly ensconced in first class, at the front of the plane. I barely even noticed we had taken off, let alone the relatively subtle roar that is the spooling of the engines at takeoff. The first was an Air France Airbus A380 from New York JFK to Paris CDG.
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