Pre-ASR engagement control for voice AI
Addressee detection vs wake words
Addressee detection decides who a device is being spoken to from natural speech, no trigger required, before ASR runs.
What each one is
A workaround vs. the actual decision.
A wake word reduces idle listening. Selective Auditory Attention (SAA) decides whether the device was actually addressed, trigger or not.
wake word detection
The workaround: a user-performed protocol
Any audio with the trigger phrase unlocks the pipeline, broadcast or not. It confirms the phrase, not who it was for.
A fixed phoneme match cannot tell a side conversation from a real command, so a phrase quoted on TV or spoken in another room passes the same as an intended trigger.
addressee detection (SAA)
The decision: is this utterance for the device?
SAA classifies addressee from acoustic signals alone, before ASR, no trigger needed. Fails closed when uncertain.
No GPU is required. Non-addressed audio is never forwarded downstream, and a DPA is available for regulated deployments.
Architecture comparison
What each layer decides, and whether it decides addressee.
VAD, wake word, and diarization each answer a different question; none decide addressee.
Each row is a real layer in the pre-ASR or post-ASR pipeline, including whether a trigger phrase is required. Only one layer decides addressee continuously.
| Layer | What it decides | When it runs | Trigger phrase required? | Decides addressee? |
|---|---|---|---|---|
| Voice activity detection (VAD) | Is someone speaking? | Pre-ASR | No | No |
| Wake word | Was the trigger phrase spoken? | Pre-ASR | Yes | Phrase-gated only |
| Speaker diarization | Who spoke and when? | Post-ASR | No | No |
| SAA addressee detection | Is the device being addressed right now? | Pre-ASR, in real time | No | Yes |
Interaction model
How each approach handles the same stream of speech.
The timeline below shows the same audio stream handled by two models. In the wake-word model, every interaction requires a trigger phrase before the command, and background audio containing the phrase causes a false unlock. In the addressee-detection model, natural speech is classified continuously: addressed turns are forwarded without a trigger, non-addressed turns are dropped, and uncertain turns fail closed.
What only SAA decides
Four things a wake word cannot do.
A wake word detects a phoneme sequence. SAA decides conversational intent. The two are not in competition: they can run together, with the wake word as an optional explicit-activation layer and SAA providing continuous addressee gating across the session.
only SAA decides
Natural speech, no trigger required
Natural speech with no keyword is still forwarded. A wake word only recognizes the trigger itself.
only SAA decides
Trigger phrase in background speech
SAA suppresses the trigger phrase in audio not addressed to the device, a distinction wake words cannot make.
only SAA decides
Continuous addressee state across speakers
Every speaker gets an independent addressee decision each turn, not only right after a trigger. In a multi-party room, SAA maintains this signal for the full session.
only SAA decides
Ambiguous utterances, fail closed
When acoustic evidence is ambiguous, SAA does not guess. Audio is not forwarded; ASR never receives it.
Performance
Measured performance on real multi-party audio.
SAA reliably classifies addressee from audio-video fusion or audio alone, on held-out multi-party sessions (arXiv:2604.08412).
It fails closed under distribution shift; cross-lingual recall is a known limitation under active work.
Every audio segment sent to ASR, LLM, and TTS costs compute, addressed or not. SAA drops it before the pipeline runs.
In QSR, cross-talk false-triggers open-mic incidents; SAA suppresses them pre-ASR. In service robotics, SAA replaces an often-impractical trigger phrase.
performance
Reliable on audio alone or audio-video fusion
Both modalities are evaluated on the same benchmark. Audio alone needs no video stream; fusion adds spatial context when a camera is present.
latency
Real-time decision, pre-ASR
No GPU required. Runs under any ASR or model stack, on any device.
design principle
Fails closed by design
Ambiguous speech is suppressed, not passed through. Under uncertainty the default is silence, not a false activation, a behavior wake words have no equivalent for.
Common questions
What teams ask before switching architectures.
Can I drop the wake word entirely?
It depends on your product design. SAA decides addressee on any natural utterance, no trigger needed. Some teams drop the wake word entirely; others run a hybrid architecture where SAA provides continuous addressee gating and the wake word stays as an optional explicit-activation layer. Nothing about SAA requires removing an existing wake word.
Why do wake words misfire?
A wake word fires whenever its trigger phonemes appear, broadcast or genuinely addressed. A phrase quoted on TV, spoken in a side conversation, or repeated by another person can all trigger a false activation. SAA adds the addressee judgment phoneme matching lacks, so it suppresses activations where the trigger phrase was present but the speech was not directed at the device.
Does SAA work alongside an existing wake word?
Yes, with no changes to your stack. SAA runs upstream, downstream, or parallel to any wake-word detector, gating everything the trigger does not. In a hybrid deployment the wake word provides explicit user activation while SAA suppresses ambient speech that contains the trigger and handles natural-speech turns after activation.
Is addressee detection slower than a wake word?
No. SAA decides before ASR begins, the same point in the pipeline as a wake word, but from a richer acoustic signal rather than a narrow phoneme match. The combined latency of SAA plus your ASR and model stack is comparable to a wake-word-gated pipeline.
What about privacy if there is no wake word?
SAA streams audio to a hosted inference endpoint; non-addressed audio is never forwarded downstream and is not retained after inference. A DPA is available for regulated deployments.
Compare the layers
How addressee detection relates to other audio pipeline layers.
Each comparison page explains one distinct architectural decision and how SAA relates to it. Together they define the addressee-detection category.
Get in touch
A path to natural, trigger-free interaction.
Tell us about your stack and we will follow up with a free evaluation on your own audio.
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Last updated June 26, 2026