LC3 and LC3plus: The New Bluetooth Audio Default

Published: 2026-06-05 · Reading time: 13 min read · Author: Nikolay Sapunov, CEO at Fora Soft

Why this matters

If you build video conferencing, telemedicine, e-learning, OTT, or any product where sound leaves a phone and arrives at a wireless earbud, you do not control the last wireless hop — Bluetooth does — and the codec on that hop sets a ceiling on the quality and latency your users actually experience. This article is written for a product manager, founder, or operations lead with no audio background: by the end you will understand what LC3 is, why it replaces SBC, how it compares on quality and battery, what LC3plus adds, and what the move to Bluetooth LE Audio means for call quality, lip-sync, and hearing accessibility in the products you ship. Every technical number traces back to the controlling standard — the Bluetooth SIG LC3 specification and ETSI TS 103 634 — or to its makers' published figures, not a secondhand blog.

The codec that finally replaces SBC

For twenty years, almost every Bluetooth headset has used the same compression engine. When sound travels from your phone to a wireless earbud, it cannot travel raw — the radio link is too narrow — so a codec squeezes it down first and expands it again at the earbud. A codec is just that: an agreed method for compressing sound on one end and reconstructing it on the other.

Classic Bluetooth audio runs over a profile called A2DP, the Advanced Audio Distribution Profile, and A2DP's mandatory, always-present codec is SBC — the Low Complexity Sub-band Codec. SBC was built in the early 2000s for one goal: make any headset work with any phone. It was designed for interoperability, not efficiency, so it needs a lot of data to sound decent — typically 192 to 345 kbit/s (SoundGuys; Bluetooth SIG). Every device has it, which is why it is the floor nobody falls below, and also why it is the bottleneck nobody could move past.

The new codec is LC3, the Low Complexity Communication Codec, specified by the Bluetooth Special Interest Group — the SIG, the body that governs Bluetooth — and developed jointly by Fraunhofer IIS (the institute behind MP3 and AAC) and Ericsson (Bluetooth SIG, Low Complexity Communication Codec 1.0; Fraunhofer IIS). LC3 is the audio engine of Bluetooth LE Audio, the next-generation Bluetooth audio architecture announced in January 2020. The LC3 specification itself was published in late 2020, and the full set of LE Audio specifications was completed on 12 July 2022 (Bluetooth SIG; Electronics Weekly, July 2022).

The one fact to hold onto: LC3 delivers the same audio quality as SBC at roughly half the data rate, and that single efficiency gain is what makes the entire next generation of Bluetooth audio — longer battery life, true wireless earbuds, standardized hearing aids, and broadcast audio — possible.

Figure 1. From SBC in 2003 to LC3 and Auracast in the 2020s. The 2022 completion of the LE Audio specifications is the moment LC3 became the new default.

What LC3 actually is, in plain terms

LC3 is a block-based transform codec (Bluetooth SIG). That phrase has two halves worth unpacking.

"Block-based" means LC3 chops the incoming sound into short slices and compresses one slice at a time. Each slice is called a frame, and LC3 frames are either 10 milliseconds or 7.5 milliseconds long (Bluetooth SIG). Think of it like a film: continuous motion stored as a run of still frames. Shorter frames mean the system reacts faster — lower latency — at a small cost in efficiency, which is why a phone call might choose 7.5 ms and music might choose 10 ms.

"Transform codec" means LC3 turns each frame of sound into a list of frequency ingredients — how much bass, how much midrange, how much treble — and then spends its limited bits only where the human ear will actually notice, throwing away detail the ear cannot hear. This is the same family of math, the Modified Discrete Cosine Transform, that powers AAC and Opus, explained in how audio compression works.

LC3 is flexible about what goes in. It accepts the standard sample rates a video product meets — 8, 16, 24, 32, 44.1, and 48 kHz — at 16, 24, or 32 bits per sample, and it places no fixed limit on the number of channels (Bluetooth SIG). The sample rate is how many times per second the system measures the sound, explained in sample rate; the bit depth is how finely each measurement is recorded, explained in bit depth and dynamic range. Crucially, LC3 lets the device choose a bitrate freely across a wide range rather than locking it to the sample rate, so a designer can trade quality against battery and radio time on the fly.

Why "half the bitrate" matters: quality and battery

The headline claim — same quality at half the data — comes from the Bluetooth SIG's own listening tests, and it is worth seeing the numbers.

The SIG ran subjective tests using the ITU-R BS.1116-3 method, the recognized standard for judging small impairments in audio, which scores quality on a 1-to-5 scale where 5 means the impairment is imperceptible (Bluetooth SIG; ITU-R BS.1116-3, 2015). In those tests, LC3 at 80–96 kbit/s consistently scored higher than SBC at 132–198 kbit/s (Bluetooth SIG, LC3 Characterization; Avantree). In one widely cited point on the curve, SBC at 345 kbit/s scored just above 4.0, while LC3 reached an even higher score at 160 kbit/s — less than half the data (Bluetooth SIG).

Why does halving the data rate matter so much to a product team? Because on a battery-powered earbud, the radio is one of the hungriest components, and radio energy scales with how much data you send. Send half the bits and you cut a large share of the transmit energy. The math is direct:

If equal quality needs ~96 kbit/s on LC3 vs ~192 kbit/s on SBC,
the audio payload over the air is halved: 192 → 96 kbit/s.

That saved energy is what buys longer earbud runtime, or lets the same battery shrink into a smaller true-wireless bud. The Bluetooth SIG built LE Audio specifically to deliver lower power consumption, smaller devices, and true wireless operation with an independent, synchronized stream to each earbud — and LC3's efficiency is the enabler for all three (Bluetooth SIG).

Figure 2. LC3 reaches a given quality at roughly half the bitrate of SBC. The gap is what funds longer battery life and the new LE Audio features. Quality axis per ITU-R BS.1116-3; curves redrawn from the Bluetooth SIG LC3 characterization data.

What Bluetooth LE Audio unlocks

LC3 is the codec, but it arrived as part of a larger architecture — Bluetooth LE Audio — and three of that architecture's features matter directly to anyone building communication or media products.

True wireless, properly synchronized. Classic Bluetooth sent one stream to a primary earbud, which relayed to the second; LE Audio sends an independent, tightly synchronized stream to each earbud (Bluetooth SIG). For a video call, that means both ears stay locked to the same moment, which protects the feel of lip-sync, covered in lip-sync windows.

Standardized hearing aids. LE Audio defines, for the first time, a single interoperable standard for Bluetooth hearing aids — so a hearing aid and a phone from different makers can work together (Bluetooth SIG). LC3's low power is essential here, because hearing aids run on tiny batteries.

Auracast broadcast audio. This is the genuinely new use case. Auracast lets one transmitter broadcast an LC3 audio stream that an unlimited number of nearby devices can tune into, like joining a public Wi-Fi — a gate announcement at an airport, the audio of a silent TV in a gym, or an assistive-listening feed in a theatre (Bluetooth SIG). Auracast depends entirely on LC3's efficiency to broadcast good sound at low power. Rollout is underway: Bristol Temple Meads became the first UK railway station to switch on Auracast in July 2025, and venues including the National Theatre and Southbank Centre have committed to Auracast by 2030 (RNID; Bluetooth SIG). On the device side, recent Samsung Galaxy phones, earbuds from Sennheiser, and hearing aids such as GN ReSound Nexia and Oticon Intent already support it.

Common mistake: assuming a wireless earbud "supports LC3"

The most common planning error is to assume that because LC3 is a 2020 standard, any modern earbud uses it. It does not work that way. LC3 lives in Bluetooth LE Audio, which is a different stack from the Classic Bluetooth (BR/EDR) that A2DP and SBC run on. A device must implement the LE Audio stack — and both ends, phone and earbud, must support it and negotiate it — before a single LC3 frame is exchanged. Many earbuds sold today still fall back to SBC or a vendor codec like aptX or AAC over Classic Bluetooth. For a product team, the practical consequences are two: do not assume your users get LC3 quality or latency just because their hardware is new, and if your app's audio path touches a wireless device, test on the real Classic-Bluetooth fallback, not only on an LE Audio bench. Designing for the SBC floor and treating LC3 as a bonus is the safe posture in 2026.

LC3plus: the high-end superset

LC3 covers mainstream earbuds and calls. For applications that need more — lower latency or higher fidelity — Fraunhofer IIS built LC3plus, a superset of LC3 standardized by ETSI as ETSI TS 103 634 (Fraunhofer IIS). LC3plus is backward compatible with LC3 in Bluetooth LE Audio, so an LC3plus device still talks to an LC3-only device (Fraunhofer IIS). It extends LC3 along three axes.

Lower latency. LC3 offers 10 and 7.5 ms frames; LC3plus adds 5, 2.5, and 1.25 ms frame durations, reaching an end-to-end latency as low as 7 ms — the reason it ships in premium gaming headsets where audio lag costs you the round (Fraunhofer IIS).

Higher resolution. LC3plus supports sample rates up to 96 kHz with total-harmonic-distortion-plus-noise as low as −132 dB, and it carries the Hi-Res Wireless certification from the Japan Audio Society, whose criteria include 96 kHz sampling, at least 24 bits per sample, and reproduction of frequencies of 40 kHz and above (Fraunhofer IIS; Japan Audio Society).

More robustness. LC3plus turns on Advanced Packet Loss Concealment by default, making it up to three times more robust against packet loss than plain LC3 — it hides missing audio frames more convincingly when the radio link drops data (Fraunhofer IIS). Packet loss concealment is the art of filling gaps when frames go missing, covered in packet loss concealment.

LC3plus already ships in real products: gaming headsets from HyperX, Audeze, and Corsair; true-wireless earbuds from Harman (JBL, AKG) and Bang & Olufsen; HiFi systems from Bang & Olufsen; and wireless microphones from Sony and AnkerWork (Fraunhofer IIS). For a content-creation or live-production pipeline, the wireless-microphone angle matters: low latency keeps captured audio in sync with video at the source.

Table 1. SBC, LC3, and LC3plus compared. SBC is the universal floor; LC3 is the efficient new default; LC3plus is the high-performance superset. Sources: Bluetooth SIG (SBC, LC3); Fraunhofer IIS and ETSI TS 103 634 (LC3plus).

Where this lands for a video product

The takeaway for anyone shipping calls or media: the wireless last hop is getting better, but unevenly, and you should plan for both worlds. On an LE Audio device, LC3 gives you cleaner voice at lower power and tighter two-ear sync; on the millions of Classic-Bluetooth devices still in use, you are on SBC and must design for its higher latency and lower efficiency. The honest planning rule is to target the SBC floor for correctness and treat LC3 and LC3plus as quality upside you detect and exploit when present.

Where Fora Soft fits in

We build video conferencing, telemedicine, e-learning, OTT, and AR/VR products, and the wireless audio path shows up in almost all of them — a doctor on a telemedicine call wearing earbuds, a learner in a noisy room, a viewer on a soundbar. The engineering work around codecs like LC3 is practical: measuring real mouth-to-ear latency across Classic and LE Audio paths, keeping a clean fallback to SBC so nobody gets silence, protecting lip-sync when each ear has its own stream, and making accessibility features like Auracast assistive listening reachable inside the product. We have made those audio trade-offs across conferencing, streaming, and telemedicine builds since 2005.

What to read next

• How Audio Compression Works: The Four Ideas Behind Every Modern Codec
• Opus: The Open Codec That Ate WebRTC
• Packet Loss Concealment (PLC): Hiding the Missing Frames

Call to action

• Talk to a audio engineer — book a 30-minute scoping call to talk through your lc3 codec bluetooth plan.
• See our case studies — 250+ shipped projects across video streaming, WebRTC, OTT, telemedicine, e-learning, surveillance, and AR/VR.
• Download the Bluetooth audio codecs - cheat sheet — One page: SBC vs LC3 vs LC3plus, the bitrate-and-quality numbers, what Bluetooth LE Audio and Auracast unlock, and the 'a new earbud does not guarantee LC3' fallback pitfall.

References

1. Bluetooth SIG, Low Complexity Communication Codec (LC3) 1.0 specification (specification page, accessed 2026-06-05). The controlling specification for LC3: defines the block-based transform codec, the 10 ms and 7.5 ms frame intervals, the 8–48 kHz sample rates, the 16/24/32-bit depths, and the unlimited-channel support. https://www.bluetooth.com/specifications/specs/low-complexity-communication-codec-1-0/
2. ETSI TS 103 634, Low Complexity Communication Codec plus (LC3plus) (V1.6.1). The controlling specification for LC3plus: the algorithm description, the additional 5/2.5/1.25 ms frame durations, high-resolution support, and Advanced Packet Loss Concealment. Software and full text published by ETSI. https://www.etsi.org/deliver/etsi_ts/103600_103699/103634/01.06.01_60/ts_103634v010601p.pdf
3. Bluetooth SIG, A Technical Overview of LC3 (Bluetooth blog, M. Afaneh, 2 November 2020; updated 2026). First-party source for LC3's technical properties (block-based transform, frame intervals, sample rates, bit depths), the four LE Audio features, and the SBC-to-LC3 quality graph using ITU-R BS.1116-3 grading. https://www.bluetooth.com/blog/a-technical-overview-of-lc3/
4. Bluetooth SIG, LC3 Characterization white paper (v1, 2023). The published listening-test data behind the claim that LC3 at 80–160 kbit/s outperforms SBC at 132–345 kbit/s, scored per ITU-R BS.1116-3. https://www.bluetooth.com/wp-content/uploads/2023/07/LC3Characterization_WP.pdf
5. ITU-R BS.1116-3 (February 2015), Methods for the subjective assessment of small impairments in audio systems. The standard scoring method (1–5 impairment scale) used in the LC3-vs-SBC listening tests; the source for the quality-axis definition in Figure 2. https://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.1116-3-201502-I!!PDF-E.pdf
6. Fraunhofer IIS, LC3 / LC3plus (product page, accessed 2026-06-05). First-party source from the codec's developer for LC3plus: backward compatibility with LC3, the 10/7.5/5/2.5/1.25 ms frame durations, the ~7 ms end-to-end latency, 96 kHz support, −132 dB THD+N, Advanced Packet Loss Concealment (≈3× more robust), the Japan Audio Society Hi-Res Wireless certification, and the partner-device list. https://www.iis.fraunhofer.de/en/ff/amm/communication/lc3.html
7. Bluetooth SIG, Bluetooth SIG Announces Completion of LE Audio Specifications (12 July 2022). Source for the completion date of the LE Audio specification set, the introduction of Auracast broadcast audio, and the LE Audio architecture (multi-stream, true wireless, hearing aids, broadcast). https://www.bluetooth.com/learn-about-bluetooth/feature-enhancements/le-audio/
8. Electronics Weekly, Bluetooth LE Audio specification complete, adding local audio broadcast (July 2022). Independent confirmation of the 12 July 2022 LE Audio completion and the Auracast broadcast capability; used as the secondary corroboration of the Bluetooth SIG announcement. https://www.electronicsweekly.com/news/design/communications/bluetooth-le-audio-specification-complete-adding-local-audio-broadcast-2022-07/
9. SoundGuys, Understanding Bluetooth codecs (accessed 2026-06-05). Used only for the framing of SBC as the mandatory A2DP baseline codec and its typical 192–345 kbit/s operating range; the LC3 quality and bitrate facts come from the Bluetooth SIG sources above, which override any vendor or editorial figure where they differ. https://www.soundguys.com/understanding-bluetooth-codecs-15352/
10. RNID, Auracast: A revolution in audio accessibility (thought-leadership report, March 2025), and contemporaneous venue reporting (Bristol Temple Meads, July 2025; National Theatre / Southbank Centre commitments). Source for the real-world Auracast rollout used in the LE Audio section; deployment framing only, with the codec facts cross-checked against the Bluetooth SIG. https://rnid.org.uk/2025/02/auracast-a-revolution-in-audio-accessibility/