An unanalyzed sound of a language. It is the smallest identifiable unit found in a stream of speech that is able to be transcribed with an IPA symbol.

• A. Phone
• B. Utterance
• C. Allophone
• D. Idiom

Answer: (A)

In phonetics, the smallest identifiable unit of speech that you can hear as a concrete sound and write with an IPA symbol is a phone. A phone is the actual articulation you hear and transcribe; it’s a concrete sound rather than an abstract category. The IPA can map each distinct spoken sound to a symbol, especially in narrow transcription. An utterance is much larger—it's a full spoken unit like a word or sentence. An allophone is a contextual variant of a phoneme, not a separate basic sound unit you would typically assign its own IPA symbol in broad terms. An idiom is a fixed expression, not a single sound. So the described unit is a phone.