Good catch ... I didn't account for that in my article.
In emulation, an audio stream is an infinitely long queue of audio samples, for which you can only have a certain amount of them known ahead of time (and that amount is itself a source of audio latency.) You usually have one, but can sometimes have more. And they can vary in their frequencies, including being pathological (the Game Boy outputs sound at 2MHz.)
In PC gaming, you probably have some kind of looping for background music; but sound effects are definitely things you can push in the smarter audio APIs (like XAudio2) all at once and have all the data available to consume whenever the audio API->OS mixer->sound card needs the data.
In emulation, an audio stream is an infinitely long queue of audio samples, for which you can only have a certain amount of them known ahead of time (and that amount is itself a source of audio latency.) You usually have one, but can sometimes have more. And they can vary in their frequencies, including being pathological (the Game Boy outputs sound at 2MHz.)
In PC gaming, you probably have some kind of looping for background music; but sound effects are definitely things you can push in the smarter audio APIs (like XAudio2) all at once and have all the data available to consume whenever the audio API->OS mixer->sound card needs the data.