The Apple-centric blogosphere has been abuzz the past week with discussion over the iPhone “ring/silent switch”. To summarize, a guy sat in the front row at a New York Philharmonic Orchestra performance. His new iPhone rang for around a minute, causing the conductor to halt the show. He claimed he had the phone muted with the hardware “mute” switch, and couldn’t understand why his alarm still went off.
I basically agree with both John Gruber’s points and Marco Arment’s (linked above), but that’s not what I’m contributing here.
On the last episode of The Talk Show, Gruber and Dan Benjamin discussed the design tradeoffs at length. During the discussion, they mentioned that you can set the iPad’s volume level to 0, but you can’t with the volume buttons on the iPhone. I understand the difference, and it’s something it took me a little while to figure out, way back in the early days of the first-generation iPhone.
Basically, the iPhone has two different volume levels: your ringer volume, and your audio playback volume. When audio is playing, or when an audio-centric app is open, the hardware volume buttons change the volume of the audio. When at the home screen with no audio playing, the volume buttons change the ringer volume. The audio level can go to 0, but the ringer volume can only go to 1. The turn the ringer off, you have to use the hardware switch.
At least as of iOS 5 (it goes back further, but I don’t remember how far), it tells you in the bezel which level you’re changing, “ringer” or “headphones”, though when playing through the speaker, there is no label.
The iPad harbors no concept of a separate “ringer” volume, and so its level can always go to zero. And with it muted, whether through the hardware switch or the software mute on the multitasking drawer, it will not make any noise at all. It has no Clock app for which to make an exception.