Glossary
Azure AI Speech
Azure AI Speech is Microsoft's cloud speech service. Microsoft now calls it Azure Speech in Foundry Tools, and its speech to text powers the online recognition behind Windows voice typing, which needs an internet connection.
Updated October 16, 20264 cited facts, each traced to its source
Also called Azure Speech services, Azure Speech.
Azure AI Speech is Microsoft's cloud speech service. Microsoft now describes it as Azure Speech in Foundry Tools, which provides speech to text, text to speech, and other capabilities through a Microsoft Foundry resource 1. Older articles may use Azure AI Speech, Azure Speech or Azure Speech services for the same service. When you read one, check its date, because the naming in Microsoft's documentation has changed.
Where it shows up in Windows dictation
Speech to text turns spoken audio into text, and text to speech does the reverse. In Windows, the service matters most through voice typing. Microsoft says Windows voice typing uses online speech recognition, which is powered by Azure Speech services 2. Microsoft also says voice typing needs an internet connection, a working microphone and the cursor in a text box 3.
The cloud link is the reason to read the privacy terms before dictating sensitive text. The Azure name tells you where the recognition runs, but it does not tell you how long audio or text is kept. For that, read Microsoft's privacy pages and the guide on Windows dictation privacy.
Example: a dictation app with a cloud engine
Suppose a dictation app sends your speech to Azure and inserts the result. It is online dictation, so the app depends on your connection. A fully offline alternative on Windows is Voice Access, which Microsoft says uses on-device speech recognition and works without the internet 4. Voice Access is built for controlling the PC and writing text by voice, so it is a different tool from voice typing, not a drop-in replacement.
Why it matters for dictation
Azure AI Speech explains why the built-in Windows voice typing needs internet access. When you compare dictation tools, ask whether recognition runs in the cloud or on the PC, and check which Azure name the tool's own documentation uses. A cloud engine works only while the connection holds. An on-device tool does not need the connection once its language files are installed, as the speech pack entry explains.
Related terms
- Online speech recognition: recognition that runs on a server, as Azure does.
- Windows voice access: Microsoft's on-device control and dictation tool.
- Speech pack (Windows): the on-device language files Voice Access downloads.
Guides that cover it
Evidence
Every number on this page, with where it comes from. Open a fact to see the exact words in its source.
- 1.
- 2.
- 3.
- 4.
Related terms
- Dictation on Windows: Voice Typing, Voice Access, AppsThe topic this term belongs to
- Copilot+ PCA Copilot+ PC is a class of Windows 11 hardware with a neural processing unit (NPU) that Microsoft says can run at 40 or more trillion operations per second. Some newer Windows AI features, including fluid dictation, require this hardware.
- Fluid dictationFluid dictation is a Windows feature on Copilot+ PCs that corrects grammar, punctuation and filler words as you speak. Microsoft says it is powered by small language models that run on the device, and that you can undo a correction by saying Revert or Undo that.
- Neural processing unit (NPU)A neural processing unit (NPU) is a specialized chip for AI-intensive processes, such as real-time translation and image generation. Microsoft says many new Windows AI features require an NPU that can run at 40 or more trillion operations per second, and a speech model can run faster on one.
- Number and grid overlays (Voice Access)Number and grid overlays are Voice Access views for clicking things you cannot name. Show numbers puts a number on each clickable item so you can say it, and Show grid divides the screen into numbered tiles that narrow the mouse pointer step by step.
- Online speech recognitionOnline speech recognition sends your voice to a cloud service that turns it into text, instead of processing it on your PC. Microsoft says voice typing on Windows uses online speech recognition, which Microsoft describes as giving more accurate recognition.
- Phi SilicaPhi Silica is Microsoft's on-device language model, which runs on the neural processing unit of Copilot+ PCs. Microsoft says it is being replaced by Aion Instruct, and its voice typing help names it as the download to watch while fluid dictation gets ready.
- Speech pack (Windows)A speech pack is the set of on-device language files that Windows needs before it can recognize speech in a language offline. Microsoft says you must download a speech pack for a language in Voice access before you can use it, and the first download needs an internet connection.
- Voice Access (Windows)Voice Access is the Windows 11 feature that lets you control the whole PC and write text by voice, not only dictate. Microsoft says it works without an internet connection after setup, and it replaces Windows Speech Recognition.
- Voice typing launcherThe voice typing launcher is the Windows voice typing setting that lets you start dictation quickly when the cursor is in a text box. Microsoft lists it among the settings you open from the gear icon in the voice typing flyout.
- Windows key + H (Win+H)Windows key + H, written Win+H, is the keyboard shortcut that starts voice typing in Windows, so you can dictate into the text box where your cursor is. Microsoft says it does not start voice typing while Voice Access is running.
- Windows on ArmWindows on Arm is Windows running on processors that use the Arm instruction set instead of x86 or x64 chips. It runs native Arm apps and many unmodified x86 and x64 apps, and Microsoft says Arm-native apps give the best performance and battery life.
- Windows Speech API (SAPI)The Windows Speech API (SAPI) is Microsoft's interface that lets Windows apps use speech recognition and text-to-speech without building the speech engine themselves. Windows.Media.SpeechRecognition is a separate API for command and control in Windows Runtime apps.