The message read-only property of the SpeechRecognitionErrorEvent interface returns a message describing the error in more detail.
A string containing more details about the error that was raised. Note that the spec does not define the exact wording of these messages — this is up to the implementors to decide upon.
const recognition = new SpeechRecognition();
recognition.onerror = (event) => {
console.log(`Speech recognition error detected: ${event.error}`);
console.log(`Additional information: ${event.message}`);
};