Dec 30 interview with Sprint CEO Dan Hesse: http://www.marketplace.org/topics/business/corner-office/sprint-ceo-dan-hesse-says-faster-data-and-higher-definition-calls-are
Spark is Sprint's beefed up data network. "Basically what it means for the customer is your phone can work about 50 megabits per second," Hesse says. "A year from now it will be double that, and two years from now, triple that. So you're talking 150 megabits per second for the phone." Hesse says that aside from a faster data network, Sprint customers should soon expect to have better quality sound on phone calls. "We have announced something called 'high definition voice,' where your wireless phone will the be better of your devices, between your landline and your cell phone. So, today, somebody with perfect hearing hears about 10 octaves. The cell phone gives you about 4 octaves. 'High definition voice' will give you 7 of those 10 octaves, so I don't think it's going to be unusual at all six months from now for people to say, 'Let's get off this landline and let's have this call on a cell phone so we can hear each other better.'"