Flutter countdown deadline audio

I have created a demo app.
based on your code.
It does what you need.
One important thing I came to realize is that during the last five seconds, instead of playing/doing pause each second, which causes sync loss between counter and audio player, start playing audio from the last 5th second and stop at or before zero and select suitable audio file that takes appx 1 second to play a sound.
You can change the audio speed to adjust and you can also look out for alternate audio player library.
You can do anything with the code.(Fork/copy-pase,etc)
Thanks 🙂

Edit :
I realized that in future, I may delete the app from the repo, hence pasting important parts of the code here.
I have assets/tick.mp3 file in the root directory.
This is my pubspec.yaml file.

name: solution_76450197
description: A new Flutter project.
publish_to: 'none' # Remove this line if you wish to publish to pub.dev
version: 1.0.0+1

environment:
  sdk: '>=3.0.3 <4.0.0'
dependencies:
  flutter:
    sdk: flutter
  cupertino_icons: ^1.0.2
  circular_countdown_timer: ^0.2.3
  audioplayers: ^4.1.0

dev_dependencies:
  flutter_test:
    sdk: flutter
  flutter_lints: ^2.0.0
flutter:
  uses-material-design: true

  assets:
    - assets/

This is my main.yaml file.

import 'dart:async';

import 'package:audioplayers/audioplayers.dart';
import 'package:circular_countdown_timer/circular_countdown_timer.dart';
import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});
  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int quizTime = 10;
  int thresholdTime = 5;
  final CountDownController _controller = CountDownController();
  final player = AudioPlayer();

  bool isAudioPlaying = false;


  // Please not that it's not called at every second change but instead
  // called on more smaller unit of second second.
  // Hence it could be called multiple times per second
  void onCountdownChange(v) {
    int vInt = int.parse(v);
    if (!isAudioPlaying && vInt > 0 && vInt < thresholdTime) {
      // Do not call setUpdate here, we don't need to rerender UI here
      isAudioPlaying = true;
       player.seek(const Duration(milliseconds: 0));
       player.resume();
    }
  }

  @override
  void initState() {
    super.initState();
    player.setSource(AssetSource('tick.mp3'));
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: Center(
        child: CircularCountDownTimer(
            duration: quizTime,
            initialDuration: 0,
            controller: _controller,
            width: 50,
            height: 50,
            ringColor: Colors.grey.shade400,
            ringGradient: null,
            fillColor: _controller.isPaused
                ? Colors.lightBlueAccent
                : Colors.redAccent,
            fillGradient: null,
            backgroundColor: const Color(0xfff5f5f5),
            backgroundGradient: null,
            strokeWidth: 4,
            strokeCap: StrokeCap.butt,
            textStyle: TextStyle(
              fontSize: 20,
              color: _controller.isPaused
                  ? Colors.blueAccent
                  : Colors.red,
              fontWeight: FontWeight.bold,
            ),
            textFormat: CountdownTextFormat.S,
            isReverse: true,
            isReverseAnimation: false,
            isTimerTextShown: true,
            autoStart: false,
            onStart: () {},
            onChange: onCountdownChange,
            onComplete: () {
              player.pause();
              setState(() {
                isAudioPlaying = false;
              });
              print("on Complete");
            }
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed:  (){
          player.pause();
          isAudioPlaying = false;
          _controller.restart(duration: quizTime);
        },
        tooltip: 'Start',
        child: Text("Start"),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}