While smart phones continue to leap forward in most areas, from intuitive assistants and speedy data connections to dazzling displays and credible cameras, they seem to be mired in the mud when it comes to improving voice quality. Even the wall phone in grandma's kitchen probably sounds better than the smart phone in your pocket.

None of the 100-plus smart phones in our cell phone Ratings earned better than a good score for voice quality, and a significant number were only fair. By contrast, none of the cordless phones merited less than a very good, and a decent number delivered excellent voice quality. (Take a look at how Consumer Reports tests smart phone voice quality for more information.)



Still, it’s amazing that smart phones sound as good as they do when you consider the following:

1. They're space-challenged

When it comes to sound quality, cordless phones have it easy. They have only one primary function—voice calls—and their larger size lets them place their large microphones and speakers as close to your mouth and ear as possible.

Smart phones, on the other hand, are a technological sausage, densely packed with cameras, radios, microprocessors, sensors, and other hardware that enables them to do all those amazing things we expect them to do. Often, the tiny speaker is wedged between the bezel and the front-facing camera, while the microphone is sometimes relegated to the bottom of the phone—or the back. That almost guarantees a less-than-ideal connection with your mouth and ear.