What technique is used to ensure that voice messages containing unusual words are received correctly?

When transmitting voice messages, static, fading, or background noise can make similar-sounding letters (like B, C, D, P, T) easily confused. To prevent errors, especially with unusual words, names, or addresses, operators spell them out using the standard ITU phonetic alphabet (Alpha, Bravo, Charlie, etc.). Speaking loudly into the microphone is incorrect because it will usually cause audio distortion, making you harder to understand rather than clearer. Mixing Morse code into a voice transmission is not standard practice for clarifying speech.