Which unit of speech is the smallest identifiable sound that can be transcribed with an IPA symbol?

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

Answer: (A)

When using IPA, you’re capturing concrete speech sounds. The smallest identifiable sound you can label with an IPA symbol is a phone—a single, distinct sound such as [p], [t], or [s]. A phoneme is an abstract category that can be realized by different phones in different contexts (these realizations are called allophones). So while you can transcribe broader categories of sound as phonemes, the most granular unit you can pin down with a symbol is the phone. An utterance is a sequence of phones, and an idiom is a fixed expression, not a unit of sound. For example, the same phoneme in English can be realized as different phones like [t] and [tʰ] depending on the word, and IPA marks those differences at the phone level.