Airbus A350 Vs. Boeing 787 Dreamliner: Which Has The Quieter Cabin?

Journalist - Steven has a varied background in communications, and it was this passion for writing combined with his in-depth knowledge of the aviation industry that led him to Simple Flying. A keen linguist, he also has experience in translation and interpreting. Based in Palma, Spain

The Airbus A350 and the Boeing 787 Dreamliner are two of the defining long-haul aircraft of the modern era, and both were designed with passenger comfort as an important part of their appeal. That includes the sound inside the cabin, where even small reductions can make a noticeable difference during a flight lasting 10 hours or more.

Airbus has made a particularly bold claim on this point, stating that the A350 can be up to six decibels quieter inside the cabin than the 787. The figure is worth examining carefully, however, because cabin noise changes with the engine, seat location, flight phase, and airline interior, meaning the claim should not be treated as a universal measurement for every Airbus A350 and every Boeing 787.

Airbus Gives The A350 A Clear Acoustic Advantage

Airbus has long promoted the A350 as the quietest twin-aisle aircraft in its class, and its published material has specifically compared the cabin with the Boeing 787. The European manufacturer has stated that the A350 XWB was up to six decibels quieter inside the cabin than the 787, while also describing the difference as important to passenger and crew comfort.

Airbus has since repeated the broader quiet-cabin claim in more recent A350 promotional material. The six-decibel figure sounds modest until the way decibels work is considered. Airbus says that a three-decibel change represents roughly a 50% difference in sound energy, so a six-decibel reduction represents a substantially larger change in acoustic energy.

That does not mean passengers will necessarily perceive the cabin as simply six units, or a fixed percentage, quieter, because human hearing responds differently across frequencies and perceived loudness does not increase in a perfectly linear way. The latest data from ch-aviation shows that Singapore Airlines is currently the world's largest operator of the Airbus A350, as detailed above.

The wording 'up to' is therefore particularly important. It indicates that the maximum difference is not a promise that every Airbus A350 will be six decibels quieter than every Boeing 787 at every seat and every point in a flight. Airbus itself has also published A350 material describing different noise reductions in different parts of the cabin, reinforcing the point that acoustic performance is influenced by where measurements are taken.

The Boeing 787 Was Designed To Be Quiet Too

It would be misleading to describe the Boeing 787 as a noisy aircraft simply because Airbus claims an advantage for the A350. Boeing designed the 787 around passenger comfort, and its own description of the aircraft highlights technologies intended to reduce the level and quality of noise inside and outside the cabin.

The US manufacturer specifically points to advanced aerodynamics, engine nacelle chevrons, and other technologies that help reduce noise. The Boeing 787 also makes extensive use of composite materials, with Boeing stating that the aircraft is about 50% composite by weight. Those materials were selected for many reasons, including weight and durability, but the composite structure also forms part of the aircraft's approach to cabin comfort.

Boeing says the 787 combines its structural design with other technologies to create a smoother, quieter ride and reduce the factors that can contribute to passenger fatigue. All Nippon Airways is currently the world's largest operator of the 787, closely followed by United Airlines, as detailed above. However, the Boeing 787's acoustic design is not limited to the fuselage material itself.

Engine noise, airflow over the airframe, vibration, cabin systems, and the interior installation all contribute to what passengers actually hear. Boeing's current description highlights serrated engine nacelle chevrons and other noise-reduction technologies, showing that the 787 was engineered as a complete acoustic system rather than relying on one material or one component to make the cabin quiet.

Why The Engines Matter

One of the biggest reasons a simple Airbus A350 vs Boeing 787 noise comparison is difficult is that both aircraft families can be delivered with different engines. The sound generated by an engine, the way that sound travels through the nacelle and airframe, and the frequencies that reach the cabin can all vary between engine types.

As a result, two otherwise similar aircraft can produce different acoustic experiences. The Airbus A350 family uses Rolls-Royce engines, with the A350-900 and A350-1000 powered by different members of the Trent XWB family. The Boeing 787, meanwhile, can be equipped with engines from Rolls-Royce, General Electric or, depending on the variant and market, other configurations within the family's certification history.

This means the aircraft type alone does not tell the whole story when a passenger is trying to predict how quiet a particular flight will feel. Engine location and operating conditions also matter. During take-off and climb, engine noise is generally more prominent, while cruise conditions can make airflow and cabin-system noise more noticeable.

The distance between a passenger's seat and the engines matters as well, so a seat near the rear of the cabin can have a different acoustic environment from one farther forward. This is one reason a single headline number cannot describe every seat on either aircraft.

The Cabin Interior Can Change The Experience

Aircraft manufacturers build the basic airframe and acoustic systems, but airlines determine much of what passengers ultimately experience inside the cabin. Seats, galleys, lavatories, partitions, overhead bins, carpets and other furnishings can absorb, reflect or transmit sound differently.

The same aircraft type can therefore feel subtly different from one airline to another even when the underlying airframe is identical. Cabin density can also affect the impression of noise. A busy economy cabin contains conversations, seat movements, service activity and other passenger-generated sounds that can easily become more noticeable than background aircraft noise.

In a quieter premium cabin, where fewer passengers are speaking or moving around, the difference in the aircraft's underlying acoustic environment can become more apparent. The Boeing 787 and Airbus A350 both offer additional comfort features that can influence how passengers judge the cabin as a whole.

Boeing highlights the 787's lower cabin altitude and higher humidity as part of its passenger experience, while Airbus promotes similar features for the A350. These factors do not directly prove that one aircraft is quieter, but they can affect whether a passenger considers a long flight relaxing and how strongly the aircraft's background noise is noticed.

What Passengers Are Likely To Notice

For an ordinary passenger, the most important question is not necessarily which aircraft has the lowest laboratory noise level, but whether the cabin sounds noticeably calmer during a long flight. On that measure, the Airbus A350 has a strong case, particularly because Airbus has specifically positioned its acoustic performance against the Boeing 787 rather than simply comparing it with older generations of aircraft.

Passengers on a Boeing 787 are nevertheless unlikely to regard the aircraft as especially loud. The 787 introduced a quieter-generation approach to long-haul travel, combining composite construction, aerodynamic improvements, engine technologies and cabin treatments. Boeing explicitly says that attention was paid to the level and quality of cabin noise because excessive noise can contribute to fatigue, making quietness a central part of the aircraft's design rather than an afterthought.

The perceived difference can also depend on expectations. Someone moving from an older aluminum widebody to either a Boeing 787 or an Airbus A350 may notice a major improvement, while a frequent traveler comparing the two newest-generation aircraft may find the distinction much subtler. Seat position, time of flight, engine setting, and the activity level of the cabin can all dominate the experience, particularly when passengers are wearing headphones or otherwise focused on entertainment.

Which Aircraft Has The Quieter Cabin?

Based on the manufacturers' published claims, the Airbus A350 has the stronger case for being the quieter aircraft. Airbus explicitly says the A350 can be up to six decibels quieter inside than the Boeing 787, and its current product material continues to describe the A350 as having the quietest twin-aisle cabin.

That gives the A350 a clear advantage on the headline comparison, provided the claim is understood in its proper context. However, there is no single universally accepted independent cabin-noise figure that establishes a six-decibel Airbus A350 advantage across every flight condition, seat location, engine variant, and airline configuration.

The most defensible interpretation is therefore that Airbus has identified a potential maximum advantage under particular measurement conditions, rather than established that every passenger will experience an A350 as six decibels quieter than every Boeing 787. For travelers choosing between the two, both remain among the quieter and more advanced long-haul aircraft in commercial service.

The Airbus A350 appears to have the edge on published cabin-noise claims, while the Boeing 787 has a sophisticated acoustic design of its own and was deliberately engineered to make long flights more comfortable. In practice, the quietest seat may depend as much on where it is located, which engines power the aircraft, and how the airline has finished the cabin as on whether the aircraft carries an Airbus or Boeing badge.