Smart & Connected Life Smart Home What Is HD Voice and How Does It Work? Learn how voice over LTE drastically improves call quality by Kat Aoki Freelance Contributor Kat Aoki has nearly 10 years worth of professional IT and troubleshooting experience. She currently writes digital content for technology companies in the U.S. and Australia. our editorial process LinkedIn Kat Aoki Updated on May 31, 2020 Smart Home Your Best Year Ever: College Tech Tips Amazon Appliances & Lighting Google Tweet Share Email HD Voice is a 4G LTE audio technology that is offered by some mobile service providers. It reduces background noise while dramatically improving the sound quality of your calls. Here's a closer look at HD Voice and how it works. d3sign/Getty Images What Is HD Voice? HD Voice is high-definition voice calling. It's wideband audio technology that offers a superior standard for calls. By extending the frequency range of audio signals, HD Voice does two things well: Produces clearer, vibrant, and natural-sounding audioReduces background noise in any environment With HD Voice, calls are clearer and crisper. This provides a better experience for everyone on a call, whether you're talking to friends or family or teleconferencing with business associates at work. How HD Voice Works HD Voice is made possible by VoLTE (Voice over Long Term Evolution) technology. Many carriers use the two terms interchangeably. VoLTE is the next generation of VoIP, a technology that enables phone service over the internet. VoLTE is similar to VoIP, except that it uses a carrier's LTE data network, not Wi-Fi, to send and receive calls. The VoLTE communication standard specifically uses the 4G LTE network, which transmits voice calls and data at the same time. Unlike calls made over older networks, 4G LTE offers far better sound quality and faster speeds. With 4G LTE technology, the sound quality you get from HD Voice is comparable to other HD Voice-enabled services, such as Skype. You enjoy richer, more human-sounding calls with HD Voice as compared to previous technologies. Another benefit of VoLTE is that you can switch from a Wi-Fi call to a VoLTE call without the call disconnecting. How HD Voice Improves Sound Quality Sound quality depends on the quality of audio frequencies. Normally, mobile calls range from 300 hertz to 3.4 kilohertz. By comparison, HD Voice ranges from 50 hertz to 7 kHz and up. This spectrum covers the entire range of the human voice. HD Voice also enhances sound quality by increasing the sampling rate (the process of converting a smooth analog signal into a digital signal). Traditional telephony samples audio at 8,000 times per second, while HD Voice samples at 16,000 per second. By doubling the width of the sound spectrum, callers hear more depth and nuance in their conversations. This leap in technology means that the improvement in sound quality is noticeable, especially in places where there is a lot of ambient noise. How to Take Advantage of HD Voice Technology HD Voice was first rolled out in 2014, and it's come a long way since then. All the major U.S. carriers, including Verizon, AT&T, T-Mobile, and Sprint, now offer VoLTE as a free service to subscribers in most major markets. Whether you can use VoLTE for HD voice calls depends on your carrier, account, location, and phone model, as well as your call recipient's carrier, account, location, and phone model. To take advantage of HD Voice (or VoLTE), check if your carrier offers it in your area and if your phone is HD Voice compatible. Most newer phones support VoLTE, and it's often switched on by default. If you have questions, contact your specific carrier for details.