Editing Soft sign (section)

=== As a vowel in Slavic studies ===
{{See also|Proto-Slavic language#Notation|Proto-Balto-Slavic language#Notation}}
In Slavistic transcription, which is a system used to represent Proto-Slavic language, the Cyrillic letters Ь and Ъ are employed to denote extra-short vowel sounds. Ь represents the extra-short /ĭ/ sound, while Ъ represents the extra-short /ŭ/ sound.

Proto-Slavic refers to the common ancestor of the Slavic languages, which was spoken around the 5th to 9th centuries AD. During this period, the Slavic languages were still in the process of diverging from a shared linguistic ancestor. Slavistic transcription aims to reconstruct the phonological features of Proto-Slavic based on historical and comparative linguistics.

In Old Slavonic orthography, which is closely related to Proto-Slavic, the soft sign (Ь) and the hard sign (Ъ) were originally used to represent the extra-short vowel sounds. These extra-short vowels were distinct from regular short vowels in terms of their duration or length.

The extra-short /ĭ/ sound represented by Ь was a front vowel, similar to the sound of "i" in the English word "bit." On the other hand, the extra-short /ŭ/ sound represented by Ъ was a back vowel, similar to the sound of "u" in the English word "put."

By utilizing Ь and Ъ in Slavistic transcription, linguists and researchers can indicate the presence of these extra-short vowel sounds in reconstructed Proto-Slavic words. This transcription system allows for a more accurate representation of the phonetic and phonological characteristics of the ancestral Slavic language.