main.dart

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void sound() => SystemSound.play(SystemSoundType.alert);

void main() {
  FlutterError.onError = (e) => sound();
  runZonedGuarded<void>(() => runApp(MyApp()), (e, s) => sound());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) => MaterialApp(
          home: Scaffold(
        appBar: AppBar(title: Text('Sound on error')),
        body: Center(
            child: ElevatedButton(
          onPressed: () => throw Exception(),
          child: Text('Exception'),
        )),
      ));
}