What is Auracast™and How Does It Work?


Auracast™ is a next-generation wireless audio broadcasting feature built on Bluetooth LE (Low Energy) Audio. Developed by the Bluetooth Special Interest Group (SIG),  Auracast can stream sound to an unlimited number of listeners, whereas Classic Bluetooth allows only one-to-one streaming of sound. For example, a smartphone, TV, or public transmitter can simultaneously stream audio to multiple Bluetooth headphones, hearing aids or other receivers making it an ideal assistive listening technology.   It also differs from classic Bluetooth in that it places lower demands for power in devices like hearing aids, ensuring longer intervals before batteries need to be replaced or recharged.

At performing arts venues, places of worship and other places where people gather, and where aural communication is integral to the experience, Auracast offers a Assistive Listening System (ALS) technology that provides comparable or superior sound quality. If being added as a supplement to an existing assistive listening system, the cost can be surprisingly low. Auracast also has applications in many settings where other systems either have limitations or are either not practical or suitable, such as in sports stadiums,airports, convention centers.

Unlike Classic Bluetooth, Auracast does not require that devices be paired to function.  With no pairing, you simply “join” a broadcast, similar to connecting to Wi-Fi . You may need an ‘assistant’ to select the desired transmission though some receivers have this facility built in.  With Auracast, many devices offer custom listening where each listener can control his or her own volume and device settings. If the receiver is hearing aids, they also "adjust" frequencies being heard to match that user's audiogram.

​How Does It Work?


Three major elements make Auracast work:

Broadcaster – An installed ALS transmitter, smartphone, TV, dongle, or other device able to transmit (stream) the sound from a  microphone, or some other electronic sound-producing device. 

Assistant -  A device or software component designed to help individuals—especially those with hearing impairments—locate and connect to an Auracast™ broadcast audio stream. Smartphones, tablets and smart watches are among such devices. They typically can be programmed to find an Auracast or can be used with third-party apps like those from JBL, Sennheiser or “Soundcores.

Receiver - Hearing aids, earbuds, earphones, a transceiver (with wired earphones or a neckloop) can function as a personal receiver. Loudspeakers will perform that function for multiple listeners.. In the case of handheld Auracast receivers such as those from ListentenTech/Ampetronic, WilliamsAV and Bettear, the receiver is built into the device.



Direct Discovery Without an Assistant

There are reports of instances where an Auracast receiver can connect directly to a stream without the need for an assistant, including some hearing aids. Testers have found, however, that not all available transmitters are compatible with the current Auracast enabled hearing aids. Those that are, provide what is called direct Auracast discovery; This allows users to scan and join Auracast broadcasts without the need for any external devices. In such instances, where there is only one Auracast stream present, once the transmitter (like the HomeSpot BA210 v2 or those from Avantree ) is active, a compatible receiver (like the Jabra Enhance Pro 20) can automatically detect and join the broadcast  The Beltone Serene, ReSound Nexia, and Jabra Enhance Pro 20, reportedly support Auracast natively—no app or phone needed for them to find and connect to certain transmitters.

Also, in practice, if a receiver already knows which stream to join (say, via a QR code or saved broadcast ID), it can often skip the assistant entirely and just tune in. This is especially useful in public venues or accessibility setups where simplicity and speed matter.


There are two types of Auracast streams

• Public Auracast streams are open to anyone within range. Think of them like open Wi-Fi networks—you don’t need a password or special permission to join. These will become common in places like transportation terminals, on trains and buses, in stadiums, or where directions are needed to guide the public.

• Private Auracast streams are encrypted and require authorization to access—this ensures that only intended users can connect. 

• Both types can coexist in the same space without interfering with each other, which makes Auracast super versatile in crowded environments.


Latency

Auracast, built on Bluetooth LE Audio, typically delivers latency (an echo) under 40 milliseconds, and in some optimized setups, it can dip as low as 20 milliseconds (ms) or less. There are reports, though, of latency in some devices considerably exceeding 50 ms. The Bluetooth SIG does not publicly specify a hard maximum latency threshold that would disqualify a transmitter from using the Auracast logo. However, the expectation for latency performance is shaped by the LE Audio specification and the use of the LC3 codec, which under ideal conditions enables extremely low latency — often ion the 20 to 30 milliseconds range 1milliseconds, and in some cases as low as 10 ms 2.  

Low latency makes Auracast excellent for real-time applications like watching videos or live presentations without noticeable lip-sync issues. However, when compared to traditional assistive listening technologies like induction loops, infrared (IR), or FM systems, Auracast is slow. According to the International Hearing Loop Manufacturers Association, FM or InfraRed ALSs will typically have latency measuring only 10ms or less, and a hearing loop will register zero or up to a maximum of 1ms for digital systems .

Wi-Fi audio, on the other hand, is a bit of a mixed bag. While it can offer higher bandwidth and better audio fidelity, its latency varies widely depending on the protocol and can range as high as 100 to even 200 milliseconds. So in terms of raw latency, Auracast is significantly faster than most Wi-Fi-based audio systems. Wi-Fi not WI-Fi ??

    NOTE:  Latency can occur, in varying degrees, in any assistive listening system, including hearing
 loops, and depends on the distance from the source or loudspeaker to where the listener is located as acoustically the sound will generally lag the electronic signal as it propagates (travels) very much more slowly. There is no way to eliminate it using earphones or earbuds but, for users of hearing aids and CIs, who have both a mic/telecoil setting and a telecoil only setting, they can use the ‘telecoil only’ setting, and eliminate most, of the echo effect, though this approach can lead to the listener having a feeling of being isolated from the environment and activity.


Compatibility

The Auracast ecosystem is still maturing, and interoperability issues are cropping up despite devices being labeled “Auracast enabled. Auracast products vary widely in stream quality depending on their intended use, codec support, and hardware capabilities. If you're evaluating devices for assistive listening, home entertainment, or public venue deployment, understanding which ones use standard versus high-quality Auracast streams is key. This is one reason some Auracast devices will not work with others that are also Auracast enabled. Even after devices pass qualification testing through the Bluetooth SIG's compliance program , there are instances where devices from different manufacturers are not necessarily compatible. For example, some receivers only support High Quality (HQ) streams (e.g. 48 kHz), while many transmitters default to Standard Quality (SQ). Auracast enabled hearing aids are designed to accept SQ streams (16 and 24 kHz sample rates – approximately 7 kHz or 11 kHz bandwidth) to ensure low battery drain but generally cannot accept an HQ stream (48 kHz sample rate/ 20 kHz+ bandwidth). International standards are currently being drafted that should address this issue but they are over 2 years away.
Here's how the two different qualities compare:
:
SQ (Low Power) Auracast (Hearing Aid Mode)

This version is tailored for battery-sensitive devices like hearing aids and cochlear implants:
  • ♦Prioritizes energy efficiency and long battery life over full-range fidelity.
  • Enables direct streaming from Auracast transmitters to hearing aids without intermediary devices    called assistants.
  • Ideal for speech and assistive listening in public venues like churches, airports, and theaters.
  • Most hearing aids that support Auracast will default to this mode to ensure all-day usability.

HQ (High Power/Fidelity) Auracast (Consumer Mode)

This version is designed for mainstream audio devices like earbuds, headphones, and smartphones:
  • Delivers rich, full-spectrum audio for better sound quality, especially for music and media.
  • Requires more power, making it unsuitable for most hearing aids due to battery constraints.
  • Often used in entertainment venues, gyms, or personal sharing scenarios.

For assistive listening purposes, an SQ transmitter would be compatible with most hearing aids but possibly not with some other receivers such as some earbuds or earphones that require HQ streams for the better fidelity that they provide at the cost of increased power consumption and increased latency. Some transmitter manufacturers, such as Avantree, provide a list of receivers that are compatible with their transmitters.

A venue planning a DIY Auracast ALS installation should explore standard quality transmitter and then compile a list of receivers that are compatible with their transmitter so that regular visitors to the venue can select compatible receivers from that list if they wish to provide their own.


Major applications of Auracast

For people with hearing loss, its use as an assistive listening technology will be the principal use for the Auracast feature in hearing aids. As it becomes more common, they will, though, also share the many other benefits of the technology with people having so called “normal hearing”. Both will be able top hear and understand the announcer over the roar of the crowd at a football game, the flight delay announcement at the airport, or hearing an announcement in some other noisy environment. Both groups will be able to wirelessly connect to the TV in the gym or sports bar showing the program or contest they want to watch. In the home, in addition to ending the battle for the remote volume control, it allows the placement of multiple loudspeakers for music without the fuss of speaker wires.


What devices are available to use Auracast

An enormous variety of devices have already been marketed that feature Auracast connectivity and the list continues to grow as this is being written. See the Auracast Capable Devices section of this website here.


Auracast Transmitters 

An Auracast transmitter is a device that sends out an Auracast broadcast. This could be anything from a smartphone, laptop, or TV to even a public address or sound system. Many modern smartphones and tablets are equipped with Bluetooth LE Audio and Auracast. For example, Samsung has confirmed that its Galaxy S23 and later, Galaxy Z Fold 5/6, Galaxy Z Flip 5/6, Galaxy Tab S9 FE and later, and even older devices with the One UI 6.1 update will support the feature.


Auracast Assistants 

Devices people already have, like smartphones and tablets, can function as assistants if they are Auracast enabled. There are also devices or apps specifically intended as assistants from such resources as JBL, Sennheiser, Soundcore, and others.  


How far out does a transmitter's signal carry?

The range for a competent transmitter can be over 300 feet, though this depends on the allowable radiated power (it is considerably lower in Europe for example). For most small transmitters, the range would likely be 65 to 100 feet with good line of sight.


How many devices can you connect to an Auracast transmitter?

The number of people who can connect to an Auracast is unlimited. With a professional-grade transmitter, the number of people who can connect to a particular Auracast is determined by the size of the room or how far away they are from the transmitter.


The Future of Auracast

As of 2024, about 91% of U.S. adults own a smartphone, according to the Pew Research Center. That’s a massive leap from just 35% in 2011, showing how quickly and deeply embedded smartphones have become in daily life. Those smartphones, supplemented by a multitude of other transmitters and receivers, promise that Auracast will become even more pervasive the classic Bluetooth as the general public joins people with hearing loss in experiencing the improved quality of life that Auracast promises to everyone.