Behind the Products: How Do True Wireless Earbuds Actually Work?

In this week’s Behind The Products, we asked RHA’s Product Development Team to explain the process behind true wireless earbuds, then we removed all the really technical stuff:

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Bluetooth has not only given us freedom from wires, but has also changed the way we use and wear audio. Now headphones can be specialised for almost any environment; from active sports to deep listening experiences. With the advent of even more advanced versions of Bluetooth, true wireless in-ears have become an essential piece of kit for many listeners. This relatively new form of earbuds not only look different but work differently from other wireless over-ears and neckband headphones.

Bluetooth Basics

Most Bluetooth headphones work fairly simply, one singular Bluetooth signal transfers data between the headphones and source device - your phone or your laptop. These source devices are also capable of staggering the video and audio streams to ensure they sync with each other - so you don't get that infuriating gap between an actor's mouth moving and hearing their words.

But with the introduction of Bluetooth 5 offering the most energy efficiency and stable connection yet, true wireless has flourished. But how do they work? It’s all got to do with the way they talk to each other.

A Mini-Net

In every set of true wireless buds, one earbud (usually the right) is considered the primary (or 'master') bud and acts as a bridge between the source device and secondary bud, creating a tiny network known as a piconet. The primary earbud manages the piconet and compensates for any delay between the buds that occurs in the audio transmission.

The Clever Bit

Audio delay (known as latency) can be a pain, so minimising this effect is crucial. To minimise latency, the buds send information to and fro to compute how long it takes to travel information around the piconet. The speed the information travels at can be affected by several factors, especially by the environment they’re used in; built-up areas busy with signals can majorly affect latency. Once the time to complete the circuit is known, it is halved, and the earbuds 'know' how long it takes for data to be transferred. Knowing the transfer time allows the primary earbud to compensate for the latency, ensuring the buds stay in sync with each other and the source device.

Source: https://www.rha-audio.com/blog/50080/how-d...