我正在尝试使用Speech-recognition，但我不断得到错误。这是我的页面：

import {Component} from '@angular/core';
import {SpeechRecognition} from '@ionic-native/speech-recognition';

@Component({
    selector: 'app-home',
    templateUrl: 'home.page.html',
    styleUrls: ['home.page.scss'],
})
export class HomePage {

    constructor(private speechRecognition: SpeechRecognition) {
        this.speechRecognition.requestPermission()
            .then(
                () => console.log('Granted'),
                () => console.log('Denied')
            );
    }

    record() {
        const options = {
            language: 'da-DK',
            prompt: '',      // Android only
            showPopup: true,  // Android only
            showPartial: false
        };
        this.speechRecognition.startListening(options)
            .subscribe(
                (matches: Array<string>) => console.log(matches),
                (onerror) => console.log('error:', onerror)
            );
    }

}

这样我得到以下错误：

RROR in src/app/home/home.page.ts(12,32): error TS2339: Property 'requestPermission' does not exist on type 'SpeechRecognition'.
[ng]     src/app/home/home.page.ts(26,32): error TS2339: Property 'startListening' does not exist on type 'SpeechRecognition'.

我用的是Ionic 4。