LE Audio products edge closer to store shelves


It’s taken nine years, but developers are about to release the first LE Audio designs with superior wireless sound. Nordic’s nRF5340 audio DK helps them achieve this

Adolf von Henselt Piano Concerto in F minor, Opus 16, published in 1846, is considered almost impossible to play even by the most skilled keyboard virtuosos in the world. Only three recordings of the play are said to exist. It’s not so much the complexity of the music that makes it difficult, although that’s far beyond most professional pianists, but rather the speed and finger contortions required to reach the notes.

According to the Classical Music website, Ludwig vanToronto, no less than expert pianist Anton Rubinstein—described as one of the greatest piano masters of the 19th century—failed to master the work, declaring it a waste of effort that required “abnormal formations of the hand”. Henselt couldn’t understand why all the fuss; his fingers were exceptionally springy and allowed him to perfect technique far beyond the physical abilities of other players.

By playing the piano concerto is not for the faint hearted, nor save it in all its glory. The piece is complex and nuanced. This makes the quality of analog-to-digital conversion during modern recording, and digital-to-analog conversion when listening through digital players, very influential on the audio experience.

Digital audio enhancement

The benchmark for high-quality digital sound is the CD. With the proper recording, a good CD player and wired headphones, hi-fi buffs can fully enjoy the experience of complicated arrangements such as piano concerto. Headphones and wireless headphones are another matter. Today’s wireless technology does not have the throughput required for pure CD quality playback, so a compression/decompression algorithm (codec) is used to reduce the required throughput. This solves the challenge of wireless streaming but leaves music lacking dynamic range, depth and vitality.

Consumers wanted better. Surprisingly, the urge for better wireless sound wasn’t initiated by music lovers, but rather by the hard of hearing. People with hearing loss have long wanted to wirelessly connect their hearing aids to smartphones and other Bluetooth-enabled devices, but the relatively high power consumption of conventional Bluetooth has proven to be a problem. Hearing aids are worn for many hours every day and only have room for small batteries. Low power consumption is therefore essential.

In 2013, the Bluetooth Special Interest Group (SIG) began work on a wireless audio project – which eventually led to Bluetooth LE (Low Energy) Audio – targeting the hearing aid ecosystem and intended to extend the life drums. But consumer audio companies soon realized that the use cases for hearing aids applied to their market as well. As a result, the LE Audio project expanded to focus not only on battery life but audio quality as well and eventually grew to become the largest specification development program ever undertaken by Bluetooth SIG. .

Shortcut to superior wireless sound

LE Audio was launched in December 2020. At the heart of the technology is the low complexity communication codec [LC3], considered one of the most advanced wireless codecs on the market. LC3 intelligently allows developers to find a trade-off between battery life and wireless sound quality depending on the target application.

The codec requires decent processing power to maximize its potential. Nordic’s nRF5340 is the perfect wireless SoC for the job. The chip includes a dedicated, performance-optimized Arm Cortex M33 application processor, as well as an M33 processor to oversee wireless connectivity. This second processor is optimized for low power consumption. The SoC comes with a Nordic Development Kit (DK), the nRF5340 Audio DK. The DK contains everything the developer needs to get started with LE Audio projects. LE Audio took a while to hit the market, but now it’s here. And it’s getting serious attention. For example, Sennheiser, one of the world’s most renowned audio brands, says it will use Nordic Audio’s Bluetooth LE technology in some future consumer products. The technology that Sennheiser uses in its products is also accessible to any developer. They can use one or more nRF5340 DKs to design, for example, headphones that support True Wireless Stereo (TWS). It’s a sound that consumers crave almost as much as pianists crave springy fingers.


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