Have you ever been on a call on your iPhone when an SMS or email or push notification came in only to experience a terrible vibration right in your ear? iPhone has a setting to enable and disable vibrate both for silent mode (ringer switch off) and in general so you can set it up to ring, ring and vibrate, or just vibrate. What you can’t seem to do is set it up not to vibrate when you’re already on a call.

What’s curious is that not everyone seems to complain about this, and some people seem to only notice it after a firmware update. Forum member iErick as well as others have all been experiencing this issue ever since they made the upgrade to iOS 4.2.1.

Every since updating to iOS 4.2.1, when I am on a call and have the phone held up to my ear…the phone vibrates for SMS notifications and such.

This occurs if the phone is on the silent setting and when the phone is set to ring and vibrate.

I recently Updated to iOS 4.2.1 on my iPhone 4 and while on a call I received 6 emails and every single time it not only made the tone but it vibrated right into my ear. It is quite annoying and my phone wasn’t even on vibrate. It is set for vibrate and ring.

Some members have never seen this issue until now and other have said they have seen this issue with other iOS firmwares. CrackBerry Kevin has been complaining about it since iOS 2 or 3.

Is this is a bug? Is this the way Apple thinks vibration mode should work? Why can’t they use the same motion and proximity sensor that turns off the screen when you’re on a call to turn off the vibration? If you’ve experienced the vibration in the ear let us know your thoughts in the comments.

iPhone Forums and let others know your experiences.

Three brand-new iPhone owners I know have asked me about this in the last week, and I’ve heard the Apple Store has gotten more than a few walk-ins who think their iPhones are busted because of this. So, what better way to start out the New Year and our new iPhone 101 series — for new iPhone owners — then with this little how-to.

The iPhone has a hardware mute switch, which lets you quickly and easily turn the ringer off and put the iPhone into vibrate-only mode. It’s located on the left side (facing the device) directly above the volume rocker. When the ring/silent switch is in-line with the volume rocker, the ringer is on. When the ring/silent switch is offset from the volume rocker, the ringer is muted (and only vibrate is on).

A bell will flash briefly on the screen when the ringer is on, a bell with a line struck through it will flash briefly when the ringer is muted.

(Note: the iPhone will still sound alarms, play iPod music, and allow apps like games to make sounds even when the phone is set to silent)