A close friend and confidant of mine once slickly donned his eyeglasses and triumphantly declared, "There's nothing quite like life in HD". With that considered, why settle for anything less when it comes to VoIP? Fortunately, many companies understand that very sentiment, with the availability of various versions of high quality, wideband audio offered under different names. The most popular and recognizable of these is 'HD voice', a reference to Polycom's software and hardware design and implementation of wideband technology. Other companies that share this name for their telephone sets are Cisco, Grandstream, and Gigaset, with other businesses overseas branding wideband audio as 'HDVoIP'.
Notable suppliers of integrated circuits for telephony are DSP Group, Broadcom, Infineon, and Texas Instruments, who include wideband in their feature portfolios. Skype as another prime example, uses a built in audio codec called Silk which allows for extremely high quality audio. The technology is growing, and in the same way we've all but discarded and shuffled aside Color TVs in favor of HDTVs, HD audio will inevitably take over communications.
If you're wondering just how clear it is, I can simply say that hearing is believing. Nothing quite compares to actually using it, but to get an idea, check out the dramatic difference in quality HD Voice makes while eliminating more than considerable background noise on a mobile VoIP call: