Bluetooth LE Audio
Bluetooth LE Audio is an extension of Bluetooth Low Energy introduced with Bluetooth 5.2. It redefines how audio is transmitted over Bluetooth by enabling high-quality, energy-efficient sound transmission using the LE radio. Key features include multistream audio, broadcast audio (Auracast), and support for the new LC3 codec.
Frequency & Modulation
LE Audio uses the same physical layer and frequency band as standard Bluetooth LE:
Frequency band: 2.4 GHz ISM band
Channels: 40 (2 MHz spacing)
Modulation: GFSK
PHY options: LE 1M, LE 2M, and LE Coded PHY
As with BLE, transmission is based on short packets with frequency hopping (FHSS), but optimized for synchronized isochronous audio streams.
Typical Applications
Bluetooth LE Audio is designed for next-generation audio products:
True wireless stereo (TWS) earbuds with independent left/right channels
Multistream audio for simultaneous transmission to multiple devices
Broadcast audio (Auracast) in public spaces such as airports, museums, or theaters
Hearing aids with low latency and better power efficiency
Voice communication with improved compression and reliability
The use of LC3 (Low Complexity Communication Codec) allows high audio quality at lower bitrates compared to SBC.
Differences from Bluetooth Classic
LE Audio fundamentally differs from Bluetooth Classic Audio (BR/EDR + A2DP/HFP) in the following ways:
Uses BLE instead of BR/EDR radio
Introduces Isochronous Channels (CIS/BIS) for synchronized audio streaming
Enables broadcasting to many receivers (Auracast)
Provides better power efficiency and audio quality with LC3
Not backward-compatible; many products implement both radios for dual support
Relevance for Testing & Certification
From a regulatory standpoint, LE Audio devices fall under the same radio standards as other BLE devices, including:
Europe: ETSI EN 300 328
USA: FCC §15.247
Other regions: ISED, MIC, etc.
Due to the high packet rate and the use of isochronous channels, additional evaluations may be required (e.g., duty cycle, spectral density).
In addition to regulatory compliance, Bluetooth SIG Qualification is mandatory for any product using Bluetooth technology and marketed under the Bluetooth name – regardless of whether standard profiles or custom implementations are used. For LE Audio, this includes testing of LC3, isochronous channels (CIS/BIS), and profile conformance. Only SIG members may use the Bluetooth name and logo after successful qualification and listing.