Call quality, however, depends on more factors than just the device. There’s the strength of the carrier’s network, your distance from a tower, and how many people are making a call at the same time. So when you throw all those variables together, the same handset on multiple carriers can deliver a different experience.
Below you’ll find voice samples from the Sprint and AT&T versions of the iPhone 4S. Like we do with CNET’s other cell phone reviews, I used the Sprint handset to leave a scripted message on a landline phone. I then took the audio from that voice mail and put it in the media player that you see below. For the AT&T 4S, I had to enlist CNET’s David Carnoy to run the same test from New York (I called from San Francisco). We don’t have a Verizon Wireless iPhone 4S yet, but we’ll repeat the process as soon as we get a device.
Listen closely and you’ll notice a difference between the two samples. I’m not a trained audio engineer, but to me Sprint’s audio is smoother, but my voice is slightly muffled. The AT&T phone’s audio has more range, but David’s voice also has a harsh, tinny quality.
Sprint iPhone 4S call quality sample Listen now:
AT&T iPhone 4S call quality sample Listen now:
Hopefully, this gives you an idea of how much a carrier’s network can affect call quality. Just keep in mind that both of these samples are snapshots in time, so your experience may be completely different. For more on the iPhone 4S, check out our full review.