Noise-cancelling wireless headsets with mic have become more and more popular. To achieve good noise-cancelling effects, noise-cancelling headphones are faced with many challenges. Among them, how to correctly select a microphone is an important basic work.
The purpose of this article, issued by Addasound, is to help readers choose the correct microphone to achieve better headphone noise cancelling performance. Surely, it can also help you better understand the principle and implementation of noise cancelling headphones.
When the ambient noise frequency is (<1 kHz) low frequency, passive noise cancellation technology cannot provide the ideal effect. Active Noise Cancellation (ANC) eliminates the original noise by picking up noise signals and generating "inverted noise" signals to achieve real-time noise cancelling. Current noise cancelling wireless headset with mic basically uses this technology to achieve noise cancelling. In noisy environments such as streets, shopping malls, subways, train stations, airplanes, high-speed trains, wearing the active noise cancelling headset will achieve very good results.
Several important indicators of a microphone include: signal-to-noise ratio (SNR), acoustic overload point (AOP), total harmonic distortion (THD), cut-off frequency, sensitivity, phase response, group delay, and current consumption. For the design of noise-canceling headphones, although all these specifications work, the key parameters that affect microphone selection are SNR, AOP, cutoff frequency, phase response, group delay and current consumption, and of course the difference of the cutoff frequency and phase response of different products is also very important.
The design of ANC headphones is difficult to be the same. Different design schemes, such as feedback, feedforward or hybrid, each has its own advantages and limitations.
For example, a microphone with an ultra-high AOP of 69dB SNR and 130dBSPL can be used. Its specifications and variations should also meet all the standards discussed in the previous sections of this document.