③, Active noise reduction technology

The active noise reduction (ANC) function is to generate a reverse sound wave equal to the external noise through the hardware noise reduction system, and neutralize the noise to achieve the effect of noise reduction.  The working principle of ANC noise reduction is that the microphone collects external environmental noise, and then the system transforms it into an inverted sound wave and adds it to the speaker end. The final sound heard by the human ear is environmental noise + inverted environmental noise.  Achieve sensory noise reduction.  ANC active noise reduction can be divided into feedforward active noise reduction (headphone applications are more), feedback active noise reduction (prone to howling), and hybrid active noise reduction.

On October 28, 2019, Apple launched AirPods Pro headphones that support the "active noise reduction" function.  AirPods Pro is a headset that supports ANC. Compared with the previous two generations of AirPods, AirPods Pro is changed to an in-ear design, providing good air tightness and firmness of wearing, and based on this brings amazing active noise reduction.  AirPods Pro solves two difficulties, one is to solve the problem of space occupation through SiP packaging, and the other is to make a ventilation system to solve the problem of pressure difference between the inside and outside of the ear to ensure wearing comfort.

At present, Android Bluetooth technology platforms have begun to support ANC. The key is to see whether the whole machine manufacturer can overcome the engineering problems and really improve the noise reduction experience.  In addition, Qualcomm CSR chip also uses software noise reduction technology, also known as CVC noise reduction, that is, the chip inside the Bluetooth headset is used to filter the signal received by the call microphone to reduce the external wind noise.  Time to work.

According to Qualcomm's "Research Report on the Status of Use in 2019", 63% of audio users pay attention to the active noise reduction function of wireless headphones.  In addition to supporting a more immersive listening experience, active noise reduction also helps reduce listener fatigue.

Looking into the future, active noise reduction will become the standard configuration of high-end TWS headphones, and gradually penetrate into the low-end.

④ Endurance technology

AirPods Pro uses a rechargeable lithium coin battery, although the capacity has increased, but because of the active noise reduction (ANC) power consumption, battery life has not improved.  Compared with cylindrical batteries, button batteries have the following advantages: high energy density, small size and light weight, long cycle life, and convenient positive and negative electrode welding and good size consistency.  The 2019 TWS headsets of Huawei, Samsung, Sony, 1MORE, BOSE and other brands also use a button battery solution.

Increased battery life can also be achieved through advanced processes, but this means high costs.  Apple's H1 chip uses a 16nm process, while the Android system is mostly 28nm process.  The technology is advanced and the power consumption is small, but the research and development and manufacturing costs are very high, requiring a large shipment to share the cost.  According to the shipments of current brand Android machines, it is difficult to support the investment of advanced technology.  The balance of power consumption and performance is a very complicated matter, and the improvement of user experience is not only on the one hand of forwarding technology.

However, there will be great progress in the power consumption dilemma of the Android system this year. The 16nm solution of the major manufacturers is already in development. The experience improvement and shipment effect are expected to bring breakthroughs, driving the Android system to a new level of competitiveness  .

⑤, intelligent technology

In addition to the functions of playing and collecting sound information, smart electro-acoustic products such as TWS headsets will also have functions such as voice control, semantic recognition, active noise reduction, sports health monitoring, virtual reality acoustics, and interconnection with other smart devices.  It can meet the needs of many complex applications in consumers' work and life.

The intelligent function of TWS headset is mainly reflected in the following aspects:

Soft and hard integration with intelligent voice assistants, such as Apple AirPods starting to support Siri, Qualcomm chip integration with Amazon Alexa, etc .; equipped with biosensors, supporting biometric motion tracking, such as Bragi's Dash Pro allows users to directly control the headset through head movements  , AirPods single earphone has about 8 sensors, a combination of voice acceleration sensors and optical sensors; there are real-time translation in multiple languages.