Q: I recently bought a second-generation iPod touch that has Bluetooth capabilities. I have tried but failed to pair the iPod touch Bluetooth with any of the Bluetooth headpieces used for cell phones. I realize the iPod touch can output in stereo but I listen to a lot of audiobooks and podcasts. A monaural sound output would be fine with me. But the 3-4 earpieces I have tried will not work. Why not?
A: Unfortunately, Bluetooth headsets made for cellular headset/handsfree audio are not compatible with the iPod touch.
Support for different Bluetooth devices and features is determined by the Bluetooth “profiles” that are available on the devices. A Bluetooth profile defines the capabilities of a device and how it communicates with other Bluetooth devices. For Bluetooth communication to occur between two devices, they must both support the same Bluetooth profile.
There are three Bluetooth profiles that are commonly used for Bluetooth audio communication. The first two, “Headset” and “Handsfree” are intended for two-way monaural audio between a headset device and a cellular phone, and are the profiles used for cellular phones and cellular phone Bluetooth headsets. The “A2DP” profile is designed to provide one-way stereo audio from your device to a set of earphones for the purpose of listening to music playback.
All models and previous firmware versions of the iPhone provide support for the Headset and Handsfree profiles for using a Bluetooth headset for phone calls. However, this capability is limited to phone-related audio; you cannot stream your iPod playback, even monaurally, to a Bluetooth headset.
The iPhone 3.0 OS has added the A2DP profile to the iPhone 3G, iPhone 3GS and iPod touch 2G, so that you can now associate an A2DP device with your iPhone or iPod to listen to your music and other audio playback. The catch, however, is that since the iPod touch does not have a phone component, there is no need for it to support the Headset/Handsfree profiles, since these are not designed for audio playback but rather voice communications. Further, even on the iPhone a Headset/Handsfree Bluetooth device can only be used for phone-related audio such as phone calls and Visual Voicemail.
Almost all phone Bluetooth headsets use the “Headset” and/or “Handsfree” profiles, which the iPod touch does not support. In order to use a Bluetooth headset with your iPod touch, you will need to find a headset that specifically supports the A2DP profile, almost all of which are stereo headphone accessories designed for listening to music.
You can find more information on the specific Bluetooth profiles supported by the various iPhone and iPod touch models in Apple’s knowledgebase article: iPhone and iPod touch: Supported Bluetooth profiles.