Angular2: Web Speech API - Voice recognition

Finally I solved creating an interface!!

export interface IWindow extends Window {
  webkitSpeechRecognition: any;
}

And:

const {webkitSpeechRecognition} : IWindow = <IWindow>window;
const recognition = new webkitSpeechRecognition();

In Angular 9, it worked me but using const speechRecognition = window['webkitSpeechRecognition']; note that the window 'w' is lowercase.