Can Active Noise Cancellation Be Installed Later in a Car?
1 Answers
Active noise cancellation is a noise reduction technology, one of the methods applied in headphone noise cancellation, and can be installed later. Here are the relevant details: 1. The active noise cancellation function works by generating a reverse sound wave equal to external noise through the noise cancellation system, neutralizing the noise to achieve the effect of noise reduction. Its principle is that all sounds consist of a certain spectrum. If a sound can be found whose spectrum is exactly the same as the noise to be eliminated, but with the phase exactly opposite, the noise can be completely canceled out. 2. The three commonly used noise reduction measures—reducing noise at the source, during transmission, and at the human ear—are all passive noise reduction. To actively eliminate noise, people invented the "active noise cancellation" technology. Its principle is: All sounds consist of a certain spectrum. If a sound can be found whose spectrum is exactly the same as the noise to be eliminated, but with the phase exactly opposite (a 180° difference), the noise can be completely canceled out. 3. The actual method adopted is: Starting from the noise source itself, efforts are made to invert the phase of the original noise through electronic circuits.
