Record audio on command until pause

I want to add a “siri like” capability to my arduino that’ll record my voice when given a command (for example “record”), and stop when it senses that I’ve stopped speaking.
I want to be able to transmit this to my PC later on for speech to text purposes.

How feasible is this?
What should I look into to get started (given that I’m new to arduino but a capable programmer and tinkerer)?