The Discovery 975 has the normal headset features, like answering, ending, and rejecting calls, plus it has voice-dial support, last number redial, call mute, and the capability to transfer calls from the headset to the phone and vice versa. It also has multipoint, which lets you connect up to two different headsets simultaneously. The Discovery 975 also features voice prompts that let you know when you've enabled or disabled call mute, the battery status, plus the Bluetooth connection status. The latter is especially handy when you wander outside your handset's Bluetooth range; the headset will automatically let you know that you've lost the connection.
We also quite like the portable leather charging case that comes with the Discovery 975. It looks a lot like a lipstick case, just as the one for the Discovery 925 did, but this one has an LCD screen that lets you know the battery life of the case and the headset. It also has a Bluetooth icon to show if the headset is connected. We like that it snaps into place securely, and that there's a lever you can press to take it out again. If you like, there's also a clip strap for the case, in case you want to attach it to your purse.
We tested the Plantronics Discovery 975 Bluetooth headset with the Apple iPhone 3G. The pairing process went quite smoothly, and we didn't even need to enter the PIN code (though this may vary depending on your phone). We have to say we were amazed with the call quality. We tested the Discovery 975 in a variety of environments: in a quiet office, in a moving vehicle, and in front of a desk fan blowing at normal speed. In all of the above situations, we heard our callers without much issue. There was a bit of static noise at times, even in the quietest scenario. We detected a low hum occasionally, as well. Still, callers' voices came through loud and clear.
Our callers said we sounded great. Our voices sounded natural, with plenty of volume in all three situations. When we were in the moving vehicle, they couldn't hear the road or engine noise at all, and didn't know we were in the car. They did detect a bit of radio music in the background, but it was quite faint.