public void OnUpdate(ISound sound)
        {
            _time += Time.deltaTime;
            var delta = _time / _durationSeconds;

            sound.GetAudioSource().volume = Mathf.Lerp(_startVolume, _endVolume, delta);

            if (delta >= 1f)
            {
                Completed?.Invoke(this, EventArgs.Empty);
            }
        }
 public void OnStart(ISound sound)
 {
     sound.GetAudioSource().volume = _startVolume;
 }