The problem is regular exposure to noise in enclosures such as inside a vehicle (in which the noise is generated by engine, tyres and airflows around the vehicle’s body), inside an aircraft (in which the noise is generated by the propulsion system and airflows around the aircraft’s body), or in noisy environments such as dwellings exposed to (air) traffic noise. This constant noise can for instance make the communication more disrupted, requiring the users to shout over the noise in order to be clearly heard. Moreover, the external audio signals (such as music, audio announcements, TV signals) have to be amplified to go over the background noise. This can indeed cause discomfort and inconvenience. One solution to alleviate this is to use the existing one-per-user active noise control (ANC) headphones to effectively suppress the background noise. However, this is not comfortable and even not allowed in some cases (e.g. driver of a vehicle). Therefore, we have been seeking an alternative solution to provide the users with a satisfactory ANC performance, but without using any over-the-ear devices such as headphones.
Regular exposure to consistent elevated noise levels has shown to be the cause for different health problems such as noise-induced hearing impairment, hypertension, sleep disturbance, changes in the immune system, cardiovascular adverse defects and even birth defects. In addition, elevated noise levels such as aircraft noise can cause stress and impairment of memory, and fatigue, and other attention and concentration difficulties, both for passengers and for pilots. Recent reports show that all these noise-related effects entail bulk of costs in the health system of many developed countries. Therefore, there is a clear need for developing a new technology that can reduce the adverse effects caused by exposure to consistent noise.
In the said noisy enclosures, the goal is to let the users control the background noise, although they are typically located close to each other. We aim at realizing such a technology without using any over-the-ear devices such as headphones, and at overcoming limitations of available technologies. The system then simultaneously provides an auditory comfort to all the users.
