iPhone 4 switches to top mic on speakerphone?

[jackblack73]

I was speaking to someone on speakerphone and she was complaining about a noise. With speakerphone on my 3G I got used to talking to the bottom of the phone, where both the speaker and mic are. It turns out the noise was my finger rubbing the top mic (which was on the bottom since I was holding the phone upside down). Based on how well she could hear me I confirmed that the top mic was active when on speakerphone. When I tapped the mics she could hear when I tapped the top one, but not the bottom one. I also sounded very distant when speaking into the bottom mic. As soon as I turned the speakerphone off, it switched back to the bottom mic. Can anyone else confirm this? I don't see why Apple would do this. Wouldn't it mean that there's no noise cancellation when on speakerphone? I'd rather have both the mic and speaker facing me at the same time when using speakerphone.

 

[Daremo]

Yes, the speaker phone uses the top mic, that I can confirm, but as to why they chose to do it it this way, that I don't know.

 

[The Californian]

Hmmmm, the only reasoning I could think of is that possibly the bottom mic becomes a noise-cancelling mic which, in turn cancels out the sound of the other persons voice coming through the speaker?

 

[California King]

Just realized that when using FaceTime, your palm will most likely be covering the bottom mic. Same thing when using speakerphone.