Audio and Video

Explained: True wireless earbuds

07 October 2020
True wireless allows for real and normal head movement, and telephone conversations can be quickly received by only touching one of the earbuds. Source: AdobeStock

Decent earphones can make a huge difference when listening to music or the news, or chatting on the phone. There has been yet another step forward in their technology and design in recent years, giving rise to true wireless earbuds. This step forward uses various technologies to decompress digital waves that originate from an audio source and turns them by vibrations into soundwaves — much occurs in the milliseconds of audio approaching one's ears. This article will explain the fundamentals of how these latest true wireless earbuds work and their importance.

What are true wireless earbuds?

In traditional earphones, electronic signals are received by cables connected to the audio source. However, true wireless earbuds, unlike standard wireless earbuds, are not connected via cable to the audio source. Rather, they employ wireless technologies to relay data to the earbud from the audio source.

Nonetheless, the widely used term "wireless earbuds" is ambiguous as it refers to earbuds that are not attached by a cable to a mobile device, but each earbud would still be linked by a cable to one another. Therefore, "true wireless earbuds" should not be confused with standard "wireless earbuds." They are wireless earbuds that are not connected to each other and the smartphone via a cable or any other physical means. All information is distributed wirelessly. These earbuds can also have full wireless charging systems that function via electrical induction.

How do true wireless earbuds work?

Much like standard wireless headphones, true wireless earbuds also receive a signal from the smartphone via Bluetooth and at around 2.4 GHz wavelength. The smartphone acts as a transmitter and the wireless earbuds act as a receiver. In wired earbuds, the signals are received simultaneously, but in wireless earbuds, one acts as a primary or master receiver and another one acts as a secondary receiver. However, there are also wireless earbuds available, which use an antenna system and make a strong wireless connection. With it, a 10 MHz signal travels from ear to ear, using the head as a medium. Moreover, the true wireless earbuds' performance can be degraded due to the connectivity problems associated with Bluetooth connectivity.

Besides controlling the communication between the two earphones and the audio source, the primary earbud also compensates for time delays in the audio signals — often referred to as latency — that can arise during communication between the earphones. To minimize the time delay, the two earbuds supply each other with information and measure how long this process has taken. When the timing is measured, the earphones realize the duration of the operation, allowing the primary earbud to counteract any delay and guarantee that the earbuds stay in sync with each other and the source unit. It should be remembered that built-up areas or busy environments can seriously impact the latency rates. As a consequence, there can be fleeting interruptions when listening to music or holding a conversation.

However, many manufacturers have found a way out. For example, there are true wireless earphones available that utilize separate right/left autonomous signaling mechanisms for each earphone instead of a traditional primary/secondary system prone to delays and noise, as illustrated above. Similar to antenna systems, these separate signaling mechanisms also assist in keeping a strong connection, in addition to balancing the sound. Furthermore, there are also true wireless earbuds in which each earbud may have a dual-mic configuration for two main purposes:

  • They assist in effective transmission of speech for commands and calls.
  • They have a built-in smart noise reduction system that records and processes environmental noise, resulting in less sensory masking in the brain that further protects the user from hearing damage or loss caused by noise.

Versions of true wireless earbuds

Currently, there are two generations of the latest true wireless earbuds. The first-gen are the ones just discussed and referred to as "true wireless" and the second-gen are known as "true wireless plus." However, both terms are being used interchangeably in the market. In the first-gen true wireless earbuds, the connection with the audio source is made using only the primary earbud. After that, the connection is made with the secondary earbud to develop a wireless stereo connection. The information from the L and R channels is collectively sent to the primary earbud, which is then forwarded to the secondary earbud.

On the other hand, the true wireless first makes a connection between both the primary and secondary earphones. This way the audio source simultaneously develops a connection with both earbuds. The integrated chip in the earphones then assists the audio source to deliver R and L channels separately to the R and L earbuds. This removes pressure on a single earbud, increases the battery life of the earbuds, enhances the connection strength and results in a smoother, crisper audio experience.

Conclusion

True wireless earphones have all the benefits of wireless technology without their limitations. True wireless allows for real and normal head movement, and telephone conversations can be quickly received by only touching one of the earbuds. Many of them come in cases integrated with smart battery charging systems. These systems charge the earbuds while not in use, which significantly improves the battery life in comparison with earbuds with no charging case. Nonetheless, it is the elimination of the most fragile and painful portion — the cable — that is not only enhancing flexibility and convenience but also helping to set true wireless earphones apart from most earphones for a longer lifespan. True wireless earbuds are indeed a revolution in the audio industry.

To contact the author of this article, email engineering360editors@globalspec.com


Powered by CR4, the Engineering Community

Discussion – 0 comments

By posting a comment you confirm that you have read and accept our Posting Rules and Terms of Use.
Engineering Newsletter Signup
Get the Engineering360
Stay up to date on:
Features the top stories, latest news, charts, insights and more on the end-to-end electronics value chain.
Advertisement
Weekly Newsletter
Get news, research, and analysis
on the Electronics industry in your
inbox every week - for FREE
Sign up for our FREE eNewsletter
Advertisement
Find Free Electronics Datasheets
Advertisement