All three carrier models of Apple's iPhone 5 (left) offer enhanced overall sound quality compared to the iPhone 4S.
While the examination is largely unscientific, CNET found that there is a perceptible difference in audio quality when using the new iPhone 5 on the nation's top three networks.
It should be noted that the following results are from an individual case and do not reflect nationwide nationwide performance, which may vary due to coverage and other factors.
After setting a baseline call made from an AT&T iPhone 4S, the publication phoned San Francisco from a street corner New York and compared voicemail recordings using all three iPhone 5 carrier models of the iPhone 5. As noted, the calls were made with the handset held normally against the reporter's ear.
The recordings clearly illustrate the difference between the iPhone 4S and iPhone 5, with the legacy model coming in a bit mushy with noticeable background noise.
Closest to the iPhone 4S was AT&T's version of Apple's sixth-generation handset, and while the unit's noise canceling feature seemed to be fairly effective, some background noise leaked through. compared to the other two carriers, AT&T's version exhibited some "graininess" and sounded the most compressed.
The call from Verizon's iPhone 5 was a bit clearer with less background noise compared to the AT&T unit, however a close listen to the recording reveals some hiss and popping.
Sprint was the clear winner with the reporter's voice coming through with a richness and clarity not heard from the competing carriers' networks. Ambient sound was a non-factor and the transmission was clean, without pops, hiss or other distortion.
With the iPhone 5, Apple released three different versions, two of which are compatible with the two different wireless technologies deployed in the U.S. The AT&T iteration uses GSM technology, the Verizon and Sprint versions both operate on CDMA networks, and all three support 4G LTE, albeit on different bandwidths.
Because all versions of Apple's handset use the same audio components, the quick test illustrates how important a provider's network is when it comes to call quality. This is especially evident when taking the identical CDMA versions offered by Verizon and Sprint into consideration.