iPhone OS Audio Routes


Getting audio signals into and out of an iPhone OS device can sometimes be a bit tricky. The information presented below outlines the available means for getting audio signals into and out of each iPhone OS device.

Available Input Routes

Built-in mic Headset input Dock input
iPhone Yes(1) Yes Yes
iPhone 3G Yes Yes Yes
iPod touch No No Yes(2)
iPod touch 2G No Yes Yes
  1. The built-in microphone of the original iPhone appears to be routed through a speech-processing codec, which limits the sample rate to 8 kHz and significantly degrades the frequency response.
  2. Using a dock connector input with the original (1st generation) iPod touch appears to require that something be plugged into the headphone jack, unless the dock connector device also supports audio output (like the Macally iVoice Pro, which, ironically, is one of the few devices that is narrow enough to allow you to plug your headphones into the bottom of the iPod).

Available Output Routes

Receiver Speaker Headphones Dock
iPhone Yes(1) Yes(1) Yes Yes
iPhone 3G Yes Yes Yes Yes
iPod touch No No Yes Yes
iPod touch 2G No Yes Yes Yes
  1. Even when using the dock connector for input, if the receiver or built-in speaker is the current output device on the original iPhone, the sample rate will be limited to 8 kHz (for input and output).

Links to additional information:


  • Doug Hales

    you guys need a limited use or some type of trail for the iphone3G.

    like the idea but won’t drop the cash without seeing it work…

  • P Arrin

    I have an iPod Touch that I assumed to be an iPod Touch 2nd generation. However, the operating system is 3.1.2. Does that mean it is a 3rd generation iPod Touch? Will it not work?

    The Belkin TuneTalk does not work with the iPod Touch.

    Do ThumbTacks work with the iPod Touch OS version 3.1.2? The website claims iPod Touch 2G.

    It looks like I just blew $75 today on SignalScope Pro. Can someone explain?

    Thank you

    • ben

      The device model and OS version are independent. Knowing that the OS version is 3.1.2 tells you nothing about whether you have a 1st, 2nd, or 3rd generation iPod touch.

      The Belkin TuneTalk works with all iPod touch models. In my experience, if you are using a 1st gen iPod touch, you need to also have something plugged into the headphone jack in order for it to work.

      The ThumbTacks mic works with iPod touch 2G or 3G (but not 1G), regardless of which version of the OS you are using.

  • P Arrin

    Thank you, Ben,

    Last night I visited the Apple community support site where I learned that the iPod Touch is 2nd generation. It has a chrome back plate with an oval transparent to EM and Settings> General> About > Model > MB528LL — in case anyone else has this question. It has an “8” GB capacity that apparently means it can’t be 3rd generation.

    A ThumbTack is on order, with a plan to try an Apple Remote Headset with Mic as you have mentioned. Will try the Belkin if neither of those works out.

    Good to know $75 was not wasted.

  • David

    Has there been any testing done on the new iTouch 4th-Gen. I know that it will not work with Macally iVoice. Dock-connector Alt. audio is only by HDMI or USB. Can SignalScope Pro work just by using 4-conductor Headphone jack on the 4th-Gen iTouch?