在重构具有多个yield的IEnumerator方法时遇到麻烦

我的代码要点如下:

// Play the first beat
audio.PlayOneShot(beat);
// Show 1st heartbeat border flash
TweenAlpha.Begin(heartbeatPanel.gameObject, 0.1f, currentStress);
yield return new WaitForSeconds(0.1f);
TweenAlpha.Begin(heartbeatPanel.gameObject, 0.5f, 0);
yield return new WaitForSeconds(interval);
// Play the second beat
audio.PlayOneShot(beat);
// Show 2nd heartbeat border flash
TweenAlpha.Begin(heartbeatPanel.gameObject, 0.1f, currentStress);
yield return new WaitForSeconds(0.1f);
TweenAlpha.Begin(heartbeatPanel.gameObject, 0.5f, 0);
yield return new WaitForSeconds(interval * 2);

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现在我想把上面的代码分成一个IEnumerator方法，有两个调用。

这是我想到的:

StartCoroutine(PlayBeat(currentStress, interval));
StartCoroutine(PlayBeat(currentStress, interval * 2));
// ...
IEnumerator PlayBeat(float currentStress, float interval)
{
     audio.PlayOneShot(beat);
     TweenAlpha.Begin(heartbeatPanel.gameObject, 0.1f, currentStress);
     yield return new WaitForSeconds(0.1f);
     TweenAlpha.Begin(heartbeatPanel.gameObject, 0.5f, 0);
     yield return new WaitForSeconds(interval);
}

这样做的问题是，这两个节拍并没有以正确的间隔发出声音，而是同时发出声音，因为我在无限循环中调用这些声音，Unity崩溃了，因为没有考虑到间隔。

将上面两个重复的代码块提取到单个IEnumerator方法中的最佳方法是什么?

yield return StartCoroutine(PlayBeat(currentStress, interval));
yield return StartCoroutine(PlayBeat(currentStress, interval * 2));