Which type of sounds can be stretched without distortion?

Continuant sounds are the correct choice because they are produced with a consistent airflow and can be elongated or stretched without changing their quality. Continuant sounds include fricatives and some approximants, which can be drawn out while maintaining their clarity. This trait makes them distinct from other sound types that may become distorted or unclear when elongated.

For instance, short sounds, such as stop consonants, are characterized by a quick burst of sound that does not lend itself to stretching since they are made by obstructing airflow completely for a brief moment. Similarly, while vowel sounds can also be stretched, they are often considered a separate category from continuant sounds in phonetics; not all vowel sounds maintain their integrity when significantly prolonged in certain contexts. Hence, continuant sounds are specifically recognized for their ability to be varied in duration without the risk of distortion.