How can the semi-in-ear TWS achieve amazing noise reduction? This was unimaginable in the past, but now, with ams technology, this dream can finally be realized.
In the early morning of October 29, Apple released its new generation of TWS headphones, AirPods Pro wireless headphones. The headphones support active noise reduction. After evaluating the headphones, the noise reduction effect of this half-in-ear TWS headphones exceeded the Bose earphone Noise reduction effect! Those who have tried it are surprised. Although the headset is priced at 1999 yuan, but users are rushing to force Apple to continue to increase production capacity. How do semi-in-ear headphones achieve amazing noise reduction? Let's take a look at the noise reduction technology of ams, a leading manufacturer of active noise reduction.
Long-term cultivation brings gains
In fact, the principle of active noise reduction technology is very simple. We all know that sound is a kind of wave. It has wave crests and troughs, both of which directly determine the sound size. According to physics theory, when two waves with the same frequency and opposite phases meet, interference and superposition will occur. Therefore, as long as we design a similar wave with completely opposite states, we can minimize the intensity and eliminate the noise.
For example, when an object vibrates upwards under force, another force actively strikes, suppressing this wave of vibration and leaving it in place. This is how active noise reduction technology works, allowing one sound wave to suppress another. This is the principle of active noise reduction. In addition to headphone applications, active noise reduction technology is also widely used in the automotive field. A large number of high-end models have applied active noise reduction technology.
Recently, Pierre Laboisseams, executive vice president of global sales and marketing of ams, was interviewed by media such as Electronic Innovation Network and introduced the active noise reduction technology of ams.
In fact, ams has been working in the field of noise reduction for more than ten years. The earliest ams provided analog noise reduction. In addition, ams also provides expertise for headphone manufacturers to help them optimize the acoustic, mechanical and electrical design of product design. . In 2016, ams completed the acquisition of Incus Laboratories, acquired new digital audio technology, and entered the field of digital noise reduction.
Pierre said that the company has accumulated a lot in the audio field. Before the release of Apple AirPods Pro wireless headphones, there was no noise reduction solution for semi-in-ear headphones. In June of this year, ams officially launched AS3460, an active noise reduction chip for semi-in-ear earbuds.
AS3460 is a digital noise reduction scheme. In addition to integrating the Augmented Hearing Engine (referred to as AHE) mainly for noise reduction algorithm operation, the chip also integrates Arm Cortex-M4F MCU for signal control. Among them, the self-developed DSP in AHE is one of the core competitiveness of the ams solution. The DSP is completely based on its own IP research and development, and has its unique advantages in related algorithm processing. This technology originates from Incus Laboratories, which was acquired earlier.
ams has accumulated a large number of digital signal processing noise reduction patents over the years. It can help manufacturers use DSP to reduce noise. The main method is to use complex filters and related algorithm technologies to perform frequency response and phase compensation in digital signal processing. Driven by these patented technologies, this solution has achieved better performance than traditional analog noise reduction solutions.
AS3460 can also bring automatic preset selection (APS: automatic scene switching) function to the chip. The specific method is to design different filters for different scenes, and temporarily store them in the chip. In actual use, APS can automatically pair the best filters for different noise scenes, bringing better active noise reduction. At the same time, the earphones using this solution can calculate the best noise reduction parameters in real time and smoothly switch according to the transfer function change caused by leakage changes between the human ear and the earphones in the process of use, so that the listening feel is natural and no POP noise.
Pierre revealed that in the future, AMS will also launch a better noise reduction solution. In addition, he believes that TWS headsets will also integrate more functions. For example, integration with biological monitoring is also a future trend. AMS has a software and hardware integration solution in this regard. , But he did not disclose further details.
According to GFK forecast, by 2020, the global TWS Bluetooth headset market size will reach 11 billion US dollars. The latest report from TrendForce's Topology Industrial Research Institute also pointed out that the global TWS Bluetooth headset shipments reached 78 million units in 2019 alone, an annual growth of 52.9%! This data has not been counted in the shipment of China ’s powerful copycat AirPods Pro TWS headsets. If you count it, this number will be very amazing!