Auracast
Bluetooth broadcast audio technology
From Wikipedia, the free encyclopedia
Auracast is a broadcast audio feature of Bluetooth Low Energy (LE Audio) that enables a single transmitting device to stream audio to multiple compatible receivers simultaneously, including hearing aids, headphones, earbuds, and smartphones.[1][2] It is a trademark owned by the Bluetooth Special Interest Group (SIG).[3]
Auracast Symbol | |
| Developed by | Bluetooth Special Interest Group |
|---|---|
| Industry | Wireless communication Assistive technology |
| Compatible hardware | |
| Physical range | Short-range wireless |
Auracast forms part of the Bluetooth LE Audio standard introduced with Bluetooth 5.2 and represents a departure from traditional Bluetooth audio connections, which typically rely on one-to-one device pairing.[2]
History
Development of Auracast began in the early 2010s within the Bluetooth SIG following collaboration with hearing aid manufacturers seeking improved wireless audio streaming with lower power consumption and broader compatibility.[1]
A key requirement was the ability to deliver the same audio stream to multiple users simultaneously, unlike earlier Bluetooth implementations that supported only point-to-point connections.[1] These efforts contributed to the development of Bluetooth LE Audio, within which Auracast provides broadcast audio functionality.[2]
By the mid-2020s, Auracast began to be implemented in consumer devices and tested in public environments such as airports and event venues.[4]
Technology
Auracast implements public audio broadcasting services, allowing multiple receivers to connect to a single audio transmitter without going through the Bluetooth device pairing process.[3]
It is based on Bluetooth LE Audio and supports transmission of one or more audio streams to potentially unlimited receivers within range.[1]
| Transmitter | Receiver | Assistant | |
|---|---|---|---|
| BAP | Source | Sink | Assistant |
| PBP | |||
| CAP | Initiator | Acceptor | Commander |
| TMAP | Sender | Receiver | N/a |
| HAP | N/a | Hearing aid | N/a |
Auracast is defined through a set of Bluetooth LE profiles and services:[3]
- Basic Audio Profile (BAP) 1.0.1[5]
- Public Broadcast Profile (PBP) 1.0[6]
- Common Audio Profile (CAP) 1.0[7]
- Telephony and Media Audio Profile (TMAP) 1.0[8]
- Hearing Access Profile (HAP) 1.0[9]
- Broadcast Audio Scan Service (BASS) 1.0[10]
- Published Audio Capabilities Service (PACS) 1.0.1[11]
Auracast transmitters use Bluetooth advertising to broadcast metadata about available audio streams, including stream name, type of content, and language.[12]
Compatible devices can display this information or automatically connect to selected streams based on user preferences.[12]
Bluetooth LE-enabled smartphones can function as assistants, allowing users to discover, select, and control audio streams on connected receivers such as headphones or hearing aids.[3]
Auracast also supports Broadcast Audio Uniform Resource Identifiers (URIs), marketed as "Scan to Listen", which allow users to connect to specific audio streams via QR code or near-field communication (NFC).[13]
Applications
Auracast is used in both consumer and public environments.
Accessibility
Auracast enables direct audio streaming to hearing aids and assistive listening devices, improving speech intelligibility in noisy environments compared to older technology such as an Audio induction loop.[2]
Public infrastructure
Auracast can be used to deliver announcements and audio content in shared spaces such as airports, transport systems, lecture halls, and entertainment venues. In 2026, Frankfurt Airport conducted a trial deployment of Auracast to stream gate announcements directly to passengers’ personal devices.[4]
Consumer electronics
Auracast functionality is being incorporated into smartphones, computers, televisions, and wireless audio devices. Some platforms, such as Windows 11, have introduced Bluetooth LE Audio–based audio sharing features supporting multiple simultaneous connections.[14]