The sound of innovation: Airbus studies noise reduction at a new acoustic lab

Airbus has a long history of pioneering advanced technology that creates new and better ways for people to fly – and now, with one new facility, innovation at Airbus has never sounded so good. 
This resource is an acoustic lab in Hamburg, Germany that for the first time allows it to investigate cabin noise and vibrations using a representative fuselage segment that approximates an A320-sized aircraft. The new test platform at the Centre for Applied Aviation Research (ZAL) is a breakthrough in noise testing – which previously was evaluated by studying isolated components or during test flights. 
"Noise is a highly sensitive topic," explained Henning Scheel, who is co-leading research at the acoustic lab. “Some noises are easy to ignore, even at high volumes. Others are deeply annoying.” 
Making Airbus aircraft even quieter 
Established to help facilitate advances that will continue to make Airbus aircraft cabins the quietest and most comfortable in the sky, the ZAL’s 8.5-metre-long fuselage demonstrator can be subjected to sound waves around its full circumference via a system of 128 individually controllable speakers. This setup was designed to replicate engine noise from existing and future propulsion concepts. 
"The acoustic lab accurately reproduces conditions that apply in flight,” Scheel said. “This allows us to examine new noise reduction measures in the cabin, rendering expensive test flights unnecessary. The acoustic chamber also offers us the opportunity to perform detailed comparisons between simulation models and real-world physics." 
With the expertise gained at the ZAL acoustic lab, Airbus’ interior noise teams are pinpointing where noise enters the cabin and how it is spread and transmitted. They then can explore how background noise can be reduced – for example, by making minor structural modifications, using different types of insulation, or applying new materials such as embedded vibration dampers that absorb noise in a specific frequency range. 
Focusing on noise 
"We will significantly shorten the development cycle for new solutions with the help of this demonstrator," added Martin Wandel, who co-leads the research with Scheel. 
The ZAL chamber can accommodate fuselage demonstrators of up to eight metres high and 15 metres long, including for Airbus’ A350 XWB and A330 widebody product lines. The initial fuselage mock-up will be thoroughly investigated before work begins on representative cabin interior components. Tests with passengers also are planned in the acoustic lab’s future.
Across the company, Airbus employees in Hamburg and Toulouse, France work on interior noise – studying the cabin, cockpit and crew rest compartments. In addition, experts in Toulouse are investigating solutions for reducing engine noise. 
At Hamburg, the acoustic lab is part of a newly-created infrastructure at the ZAL, which opened earlier this year as the technological research and development network for the Hamburg metropolitan region’s civil aviation industry. The ZAL functions as an interface between the aviation sector, academic and research institutions, and the City of Hamburg – with Airbus Operations GmbH being one of the three largest shareholders.