Arc-Transcriber

Discover how one-model streaming speech transcription links names and data in real time

Most speech transcription treats names as just sounds, then needs a second pass to figure out who you meant.

4 min readMachine Learning

The conventional pipeline for speech transcription, automatic speech recognition, then named entity recognition, then entity linking, then a language model pass, works well enough until you need answers in real time. Arc-Transcriber collapses that chain into a single model that returns transcript, linked names, numbers, speaker roles, and dialog tags every 100 milliseconds. That is not an incremental improvement. It is a structural shift in how we think about streaming speech data, and it deserves serious attention from anyone building voice-enabled workflows.

What makes this approach distinct is the live fact-checking. The model takes a list you provide, a contact roster, product catalog, or set of meeting attendees, and links names as they are spoken. New names are flagged instantly. Numbers carry their semantic context: scores, clock times, monetary values. The system also identifies channel issues like clipping or telephone audio and tags whether speech was directed at an assistant. With over 200 trained decision heads, the model is doing work that previously required a stack of separate services running in sequence. The latency savings are obvious. The architectural insight is more significant: by embedding domain-specific knowledge directly into the model's heads, the system avoids the drift and inconsistency that plague multi-model pipelines. This is especially relevant given the industry trends we have been tracking. Nvidia recently opened its models so enterprises can run AI agents anywhere, signaling a broader move toward customizable, on-premises AI. Arc-Transcriber fits that trajectory neatly. Meanwhile, Block demonstrated that voice AI can run locally on a MacBook M4 Max, reinforcing that local deployment is no longer a compromise. Arc-Transcriber already runs on-device in a Mac app, and the creators use it for voice search over 61,000 books, priming the model with matching titles while the user is still speaking.

For practitioners, the practical consequence is a reduction in system complexity. If you are currently stitching together ASR, NER, entity linking, and a lightweight LLM for dialog act classification, you are managing at least four separate models, their deployment environments, and their latency budgets. Arc-Transcriber replaces that with one model and one inference call per 100-millisecond window. The trade-off is that you must supply the list of known entities upfront, and the model's performance depends on the quality of that list. That is not a limitation; it is a design choice that prioritizes precision over open-ended guessing. The two available variants, Arc mini using a Moonshot pretrained encoder and Arc-v1 using Parakeet, give teams options based on their compute constraints. The weights are on Hugging Face, the code is on GitHub, and the CLI is ready to run.

The open question is how this architecture scales to larger, more dynamic entity lists. The current demo with 61,000 book titles is impressive, but enterprise deployments often involve tens of thousands of contacts, product SKUs, and internal project names that change weekly. If the model can handle list updates without retraining, this approach becomes a genuine alternative to the pipeline status quo. If not, the upfront investment in list maintenance may offset the latency gains. We will be watching for benchmarks that compare Arc-Transcriber against a standard pipeline on identical hardware, measuring both accuracy and end-to-end latency under real-world noise conditions.

From Machine Learning

I built Arc-Transcriber, which does ASR-NL in 1-step. Every 100 ms, one model returns the transcript plus:

- Names linked to a list you give it (a roster, contacts, product names); new names are flagged "not on the list" - Numbers with their values (scores, clocks, money, dates) - Speakers and roles; - Sound and channel events (telephone audio, clipping, poor audio) - Whether the speech was addressed to an assistant. - Inbuilt tags for dialog act, speaker segmentation and more. Total 200+ trained decision heads.

Read the original at Machine Learning