ReferenceError：未定义SpeechRecognition

Question

我正在使用以下语音识别库-

https://github.com/kamiazya/ngx-speech-recognition

组件providers

providers: [
{
      provide: SpeechRecognitionLang,
      useValue: 'en-US',
},
{
      provide: SpeechRecognitionMaxAlternatives,
      useValue: 1,
 },
 SpeechRecognitionService,
 RxSpeechRecognitionService ],

这是service的呼吁声援

openVoiceRecognition(){
        this.service
      .listen()
      .pipe(resultList)
      .subscribe((list: SpeechRecognitionResultList) => {
        let message = list.item(0).item(0).transcript;
                this.searchProductFromAPI(message);
      });
    }

一切正常，除了终端机出现以下错误-

  

ReferenceError：未定义SpeechRecognition       在RxSpeechRecognitionService.SpeechRecognitionCommon

我认为，我在那里缺少一些东西。预先感谢！