Speech Recognition customize engine question on Windows about sapi

Question

Hi MSFT member,

On windows, when developing a Speech recognition app, there are about three solution APIs:

1. Windows.Media.SpeechRecognition
2. System.Speech Programming Guide for .NET Framework
3. Microsoft Speech API (SAPI)

Since We want to use local offline solution, Azure speech service is not included.

Q1: Does OEM can customize SR engine？and how to make a custom SR engine with ASR AI model? Do you a guide document to make a SR engine? Is there any restriction?

Q2: If we can custom the ASR AI model, can we config where the model is running, such as CPU/GPU/NPU/eNPU?

Q3: For Windows.Media.SpeechRecognition,System.Speech.Recognition and Microsoft Speech API (SAPI), where are their default model running? CPU, GPU or even NPU?

Q4: Are there any permission restrictions on the use of these APIs?

thank you very much