Active Noise Cancellation
Actively suppressing disturbing ambient noise
Audio playback and communication in noisy environments is always problematic – whether you are listening to music through headphones on the train or using a hands-free system in your car. To obtain the best possible audio and voice quality, disruptive ambient noise needs to be suppressed. Today’s manufacturers of audio and communication devices achieve this through not only passive isolation of the interfering noise, but also – and especially – active noise cancellation (ANC). Here, the useful signal – the sound and speech transmitted – must remain unchanged, while intelligent talk-through functionality ensures that warning signals in road traffic or announcements can still be heard.
Transferring this complexity to the measurement laboratory
To evaluate ANC performance, manufacturers have to think about how microphones and loudspeakers are arranged in relation to people. In the case of headphones, a fixed distribution exists between the ear, loudspeaker and microphone for capturing the noise. The situation in cars, however, is more complex. Configurations involving multiple microphone arrangements are used, the driver’s head moves and the loudspeaker setup impacts multiple occupants simultaneously.
In addition to measurements of electroacoustic parameters, amongst others, the following questions are relevant:
- How do I create realistic test scenarios in the laboratory that cover background noise, reverberation and interfering talkers?
- How does the system / active noise control respond to changes in the interfering noise, especially if these are rapid or sudden?
- How well does the device block out ambient noise when the ANC is activated and deactivated?
- How effective are talk-through and other functions – including safety aspects?
Intelligent testing of ANC performance
In the laboratory, the unique combination of our measurement, analysis and simulation techniques offers manufacturers the following benefits:
- Binaural recording and playback systems
- Realistic simulation of background noise and reverberation at different points in the sound field (multi-point noise simulation (MPNS))
- Complex test scenarios taking into account interfering talkers and varying talker positions
- Powerful interfaces for standard and cutting-edge transmission technologies (e.g. A2B®, Bluetooth®)
- Methods for evaluating listening effort and speech intelligibility
- Automated and reproducible tests of all relevant electroacoustic parameters (e.g. HQS-ANC-Headset)
Relevant Products
ACQUA Standards
(60000,60003,60004,60005,60009,60010,60013,60014,60018,60019,60020,60021,60023,60026,60028,60030,60032,60033,60035,60036,60038,60039,60041,60043,60044,60046,60047,60049,60055,60057,60058,60060,60062,60063,60064,60065,60066,60067,60068,60069,6711,6741,6742,6750,6770,6772,6777,6783,6788,6789,6794,6795,6796,6797,6798)
