Hi Bill,
I’m really stuck at the moment on this issue, because I’m unable to find any documentation that covers how to control the noise-cancelling mic.
I understand that you don’t believe that noise cancellation is the cause of the problem, but at the same time, the results I’m seeing are very convincing that this is actually cancelling the audio.
If the problem is not related to noise cancellation, can you suggest what it might be, and where I can look for a solution?
Paul Nettle
Creator of Break Speed
MyBreakSpeed.com
From: coreaudio-api-bounces+pnettle=email@hidden [mailto:coreaudio-api-bounces+pnettle=email@hidden] On Behalf Of Paul Nettle
Sent: Thursday, July 01, 2010 4:18 PM
To: William Stewart
Cc: email@hidden
Subject: Re: Disabling dual-mic noise suppression in iPhone 4?
Hi again Bill,
I suppose then that I am confused as to why the same app would receive such different audio results from the iPhone 4 device, when compared to all other devices (iPod 2nd & 3rd gen, all iPhones.)
Paul Nettle
Creator of Break Speed
On Jul 1, 2010, at 11:51 AM, Paul Nettle wrote:
Bill,
You are correct that it is using the bottom mic. However, it is also using the noise suppression mic to reduce ambient nose.
No Paul, it is not. That is not engaged at all times but only in limited use cases (for instance, a phone call is one case where this is engaged), and not in any use case that is available to an application at this stage.
My app (Break Speed) allows the user to view/pan/zoom into the recorded waveform. You can see a clear difference. In fact, I compared the difference between an iphone 4 and a 3gs in a noisy environment and the iphone 4 did a very impressive job of supressing the ambient noise to nearly a flat line.