private float Test1()
{
    SimpleTimer.Create(3f, () =>
    {
        //Do something
    });
}

//increase the pitch if 5 seconds have not elapsed since the last call. Otherwise return restarted pitch
private static SimpleTimer _timer;
private static float _currentPitch = 1f;
private float GetPitch()
{
    if (_timer == null)
    {
        _timer = SimpleTimer.Create(5f, () =>
        {
            _currentPitch = 1f;
            _timer = null;
        });
    }
    _timer.Restart();

    _currentPitch = Mathf.Clamp(_currentPitch + 0.05f, 1f, 2f);
    return _currentPitch;
}