Bluetooth has become one of the mainstream wireless transmission technologies. In recent years, products that use Bluetooth technology to transmit audio, such as wireless headsets, wireless speakers, and other products, have ushered in the rapid growth of the market. With the launch of a new generation of Bluetooth LE Audio technology by Bluetooth SIG (hereinafter referred to as LE Audio), this new technology will bring revolutionary changes to the application of wireless audio transmission. This paper will analyze the technical characteristics and development trends of LE Audio for you.
Bluetooth devices will usher in rapid market growth
At present, Bluetooth technology has been widely used in various technology products, from wireless audio and wearable devices to asset tracking and network lighting control solutions. Bluetooth technology can continue to meet the requirements of consumers, businesses, and industrial cases. According to a report from ABI Research, the shipment volume of Bluetooth devices reached 4.7 billion in 2021. Analysts predict that the annual shipment volume of Bluetooth devices will increase 1.5 times from 2021 to 2026, with a compound annual growth rate (CAGR) of 9%, and the shipment volume will reach 7.0 billion in 2026.
Today, from smartphones to tablets and laptops, all key platform devices include Bluetooth Classic and Bluetooth Low Energy (LE) radios. Bluetooth technology eliminates the trouble of connecting wires for headsets, speakers, in-car systems, and other devices, brings changes to the audio field, and completely changes the way people use media and feel the world. In 2022, the shipment volume of Bluetooth audio streaming devices will reach 1.4 billion. It is expected that the annual shipment volume of Bluetooth audio streaming devices will increase 1.4 times to 1.8 billion from 2022 to 2026.
Bluetooth SIG launched a new LE Audio technology on the basis of two decades of innovation, which will enhance the performance of Bluetooth audio, increase the support for hearing aids, and realize the new Bluetooth function of broadcast audio, which will once again change the way we experience audio and connect us to the world in an unprecedented way.
Higher audio quality with lower power consumption
LE Audio will provide higher audio quality with lower power consumption, enable audio developers to meet the growing performance requirements of consumers, and drive the continuous growth of audio peripheral markets (headsets, earbuds, etc). LE Audio's low-power features will also support new audio peripherals – such as wider hearing aids that support Bluetooth®; – and provide greater flexibility for better shaping. With LE Audio, there will be smaller and more comfortable hearing devices with less intrusive, so as to improve the life of people with hearing loss.
LE Audio will also add broadcast audio, a new feature that allows audio source devices (such as smartphones) to broadcast one or more audio streams to an unlimited number of audio receiving devices (such as earbuds, speakers, hearing aids, etc). This new feature will provide a unique audio experience, such as personal and location-based audio sharing, and enable Bluetooth technology to be installed in public places, enabling people to interact with audio in a variety of public places and environments in an unprecedented way.
The first batch of products using LE Audio is expected to be released in 2022. This new generation of technology will be compatible with any device equipped with Bluetooth 5.2 or later, which means that most mobile phones and audio devices in the past two years should be able to upgrade to Bluetooth LE Audio through firmware updates.
New audio codecs can improve quality and reduce cost
In addition to improving its functions, LE Audio also launched a new audio codec called a low complexity communications codec (LC3), which aims to replace the SBC codec as a new benchmark. LC3 is a royalty free wireless codec, which not only can provide better sound at the data rate of most current Bluetooth earbuds, but also maintain this quality in the use cases where the bit rate needs to be reduced. Due to the more advanced compression algorithm, the earbuds and headphones switched from the SBC to the LC3 codec and will have better sound quality, while devices with reduced data rates will benefit from prolonging battery life without sacrificing much in quality.
It is worth noting that Bluetooth uses the same 2.4GHz spectrum as Wi-Fi, cordless phones, and baby monitors, and the congestion of radio waves may lead to signal loss. In order to reduce the loss, the LC3 codec also includes a packet loss concealment (PLC) algorithm. When some audio signals are lost due to interference, the algorithm will automatically try to fill up gaps in the audio, which will achieve more stable sound quality performance.
Looking forward to the future, some low-level earbuds and headphones will adopt the LC3 codec and give up support for LDAC and even aptX, which means that the battery life of wireless audio will become better, and it may also mean that the price of some high-quality earbuds and headphones will decline because there is no need to pay the license fee for aptX and LDAC.
Google's Android 13 has supported LC3 in the beta version, which indicates that Bluetooth LE Audio will be fully supported in the full version in 2022, and Microsoft Windows is another candidate who may adopt the complete LE Audio suite. Once the software and firmware updates are launched, LE Audio earbuds are expected to provide a better user experience on these devices.
Multiple streaming technology brings new technology and application changes
In addition to exciting LC3 technology, multi-stream audio technology will also bring new technological changes. The current implementation of Bluetooth audio wireless earbuds cannot separate the left and right channels into the appropriate earbuds independently. Each pair of Bluetooth earbuds in the market must rely on customized solutions to solve this key limitation.
Looking forward to the future, Bluetooth LE Audio wireless earbuds will connect the earbuds of the left and right channels simultaneously with multi-stream audio technology, which will greatly reduce the delay between earbuds (within microseconds) and improve the connection speed, and theoretically mean that one earbud will not run out of power faster than the other. Multi-stream audio technology can also transmit more than two channels of multi-channel signals, and broadcast complete surround sound or spatial audio data without customized software.
In addition, multi-stream audio will support the transmission of multiple independent and synchronous audio streams between an audio source device (such as a smartphone) and one or more audio receiving devices, so it can support some new applications that were impossible before, such as providing a better stereo experience by using multiple data streams available, making more seamless use of voice assistant services and more smoothly switching between multiple audio source devices, and can also maintain multiple connections with earbuds, headphones, and Bluetooth speakers at the same time.
Broadcast function supports audio sharing to bring more convenience
LE Audio will also support the broadcast audio function, enabling the audio source device to play one or more audio streams to countless audio receiving devices. Broadcast audio opens significant new opportunities for innovation, including support for a new Bluetooth use case – audio sharing. For example, through personal audio sharing, people can share their Bluetooth audio experience with people around them, and family and friends can share music on the same smartphone. In addition, through location-based audio sharing, public places such as airports, bars, gyms, cinemas, and conference centers will be able to share Bluetooth audio, in order to enhance the tourist experience.
For example, people will be able to choose to listen to audio played by TVs in silent mode, because the TV will constantly send out Bluetooth signals, but will not disturb guests trying to listen to their own music or work quietly. The broadcast audio source can also be inserted dynamically. For example, if you are at an airport or train station, you can choose to receive regular updates from the departure gate without manually switching between a mobile phone and the gate signal.
Based on its low power consumption, high quality, and multiple streaming capabilities, LE Audio adds support for hearing aids. LE Audio will support the development of Bluetooth hearing aids and bring all the advantages of Bluetooth audio to more and more people with hearing loss. Places such as cinemas and lecture halls will make LE Audio transmitters available to guests who need hearing aids. These guests do not have to rent or buy special hearing aids (usually mono channel sound) at the ticket office. They can seamlessly access the audio signal of the cinema and connect seamlessly with their own earbuds or hearing aids to obtain complete stereo or even surround sound, and audios in multiple languages.
In addition to hearing aids, the remote control is also a device that can significantly benefit from LE Audio. At present, TV remote controls with embedded microphones must rely on classic Bluetooth transmission when used for voice commands. Therefore, the voice command performance on most non-premium Android TVs is poor, but LE Audio can solve this problem by providing faster and more efficient data transmission.
Conclusion
With the reduction of power consumption and cost, Bluetooth technology has become standard devices for many electronic products. The new generation of Bluetooth LE Audio technology will provide a more advanced and license-free LC3 codec, multi-streaming technology, and broadcast audio functions, which can bring more new-generation audio application modes and bring revolutionary development and changes to Bluetooth audio applications. The future of the market development is worth looking forward to.