In-depth evaluation of Bluetooth headset in 2023

  True wireless Bluetooth headset can block noise and let us listen to our favorite music, podcasts and audio books. However, sometimes external interference, the sound of airplanes, traffic and crowds will affect our listening experience. If we want to avoid all these noises, we should consider active noise reduction (ANC) headphones.

  Now, the huge gap that once existed between Bose and other audio manufacturers has finally narrowed enough for Bose to face fierce competition in this field. Now is a good time to consider noise-reducing headphones. Headphones from other manufacturers have high-quality noise reduction function. In addition, these brands provide high-quality sound.

 So, here's what you need to know when buying a Bluetooth headset:

 Active noise cancellation (ANC) and passive noise isolation

 Many headphones claim to provide noise isolation or noise cancellation, but this does not mean that they provide real noise cancellation in the form of ANC.

 Passive noise isolation, sometimes called passive noise reduction, is a fashionable term to describe the function of headphones. Simply put, elements that block sound, such as thick memory foam ear pads sealed around the ears, reduce the environmental noise we passively perceive (without using batteries). We can say that putting your finger in your ear is passive noise isolation.

 The situation of active noise reduction is more complicated. It uses a microphone to actively sample the ambient noise and generates an inverted wave that can basically eliminate the noise. If we have a perfect sine wave and play it back with its reverse (opposite mirror image), we will get any wave. In any case, ANC is very effective in removing (almost) all middle and low frequencies.

 Almost all ANC headphones use passive noise isolation to some extent in addition to the active circuit, because it is a simple method to make noise reduction more effective, and ANC usually does not suppress high-frequency noise like passive noise reduction. One of the main reasons is that ANC usually can't suppress high-frequency noise like passive noise reduction in middle and low frequencies.

What is the function of noise cancellation?

 If we have never used ANC headphones, we need to know this. Active noise reduction equipment can reduce the volume of environmental noise, but it can't be completely eliminated, and its effect in eliminating inconsistent noise is even worse.

  What does this mean? Most low-cost ANC headphones do a good job of suppressing the noise of noisy planes, trains, air conditioners and fans. However, these sounds are consistent and relatively unchanged. These circuits can easily reduce the sound of middle and low frequencies with little change. However, noise such as music, conversation and dog barking may be a problem for ANC. With the best noise reduction function, these sounds have been eliminated to some extent, but it is still possible to hear some of them.

 Should white noise be added to eliminate noise?

 Some ANC will add white noise (hiss) to the signal. The effect of ANC in the middle and low frequency is much better than that in the high frequency, so it is very important to passively reduce the high frequency noise. This kind of hiss is actually a bit deceptive, even if you add another piece to improve the silence.

  When ANC is activated in a very quiet environment, hissing can be detected. In this case, the effect of hissing is the opposite of noise elimination, that is, it is louder than the same quiet room. Most hisses are not a serious problem, even when music is playing. Generally speaking, however, the better the noise reduction effect, the less hiss you will hear.

  Please note that some people feel pressure in their ears when using ANC with high volume, while others do not. Before buying expensive products, it is worth trying some headphones in the store.

In-ear and out-of-ear noise reduction

  The most effective ANC usually appears in earmuffs. In earmuffs, the cushion acts as a barrier and forms a seal around the ear. However, the less common in-ear ANC is considered more comfortable and usually more compact because it eliminates a lot of environmental noise.

 In recent years, in-ear ANC has also been greatly improved. Headphones seal the ear canal, so high frequency can be eliminated more or less before ANC is started. At this point, whether one style is better than the other has nothing to do with ANC performance, but with personal preference and comfort. As for wireless headsets, true wireless design is under way, and reliable ANC options are emerging in this field.

Noise reduction application

 Many noise-canceling headphones allow you to use free applications to modify ANC performance to suit your environment. Most ANC models have an environmental mode, which allows us to listen to the surrounding sounds and talk to people nearby without taking off our headphones. This is a useful and almost ubiquitous function, but some manufacturers have made it possible to mix ANC and environmental levels to suit our preferences. If you have this function, it is usually through a slider in the application.