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# What is HD Voice call quality?


# HD Voice Technology: What It Is and How Phone2 Uses It

## 1. What is HD Voice?
HD Voice (High-Definition Voice) is a telecommunications technology designed to improve call clarity and quality. It utilizes **wideband audio codecs** to transmit sound over a broader frequency range (50 Hz to 7 kHz or higher), resulting in crisper, more natural-sounding conversations. This technology also reduces background noise, making it a key feature in modern VoIP systems.
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## 2. How is HD Voice Different from Basic VoIP Codecs or Voice Quality?
HD Voice outperforms basic VoIP codecs (e.g., **G.711**) in several key ways:

- **Wider frequency range**: HD Voice captures more of the human voice’s natural sound.
- **Reduced distortion**: Background noise and other audio artifacts are minimized.
- **Better call comprehension**: Higher clarity ensures less need for repeating phrases.

HD Voice uses advanced **wideband codecs** like **G.722** and **AMR-WB (Adaptive Multi-Rate Wideband)**, which operate at a broader frequency range than standard narrowband codecs. This results in a superior audio experience ideal for professional and customer-facing communication.
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## 3. Does Phone2 Use HD Voice?
**Yes!** Phone2 integrates HD Voice technology to ensure crystal-clear communication for our users. HD Voice is built into our **server-side infrastructure** and seamlessly integrated across the Phone2 apps. This ensures that every call benefits from exceptional clarity and reduced noise.

Phone2 leverages Telnyx’s advanced CPaaS infrastructure, including **wideband audio codecs** like **G.722**, to deliver high-definition audio. Whether you're using local or toll-free numbers, HD Voice enhances your calls by:

- **Minimizing background noise**.
- **Providing lifelike, natural audio quality**.
- **Optimizing performance**, even in low-bandwidth environments.

HD Voice is just one way Phone2 ensures reliable, high-quality VoIP communication tailored to your business needs.
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## 4. Which Wireless Networks Support HD Voice?
Most modern wireless networks support HD Voice, particularly those built on **LTE (Long-Term Evolution)** and **5G** technology. These include:

- **AT&T**: HD Voice is available on VoLTE-enabled devices for domestic and international calls.
- **Verizon**: Supports HD Voice on its VoLTE network for high-quality audio.
- **T-Mobile**: Offers HD Voice across its LTE and 5G networks.
- **Sprint (now part of T-Mobile)**: HD Voice is supported for devices compatible with T-Mobile's infrastructure.

For HD Voice to work on wireless networks, both the caller and recipient need HD Voice-enabled devices, and the call must be routed over a compatible network like VoLTE or 5G.