Old National Pronunciation

The artificial nature of the system proved impractical, and in 1926 a decision was made to normalize the pronunciations to the natural pronunciations found in Beijing, which resulted in a revised Guóyīn Chángyòng Zìhuì (國音常用字匯, "Vocabulary of National Pronunciation for Everyday Use") published in 1932.

Phonology

The Old National Pronunciation was similar to the phonology of the Beijing dialect, but with four additional distinctions derived from Middle Chinese that were still maintained in other dialects:

1. Three more initials, derived from the initials of Middle Chinese: 微 , 疑 as two initials, and .
2. Preservation of the "round-sharp distinction" (traditional Chinese: 尖團音; simplified Chinese: 尖团音; pinyin: jiān-tuán yīn). The alveolo-palatal initials of the Beijing dialect (), written in pinyin as j, q and x, originated in a merger between velar initials () and alveolar affricates () before the front vowels and . In the Old National Pronunciation, the former group were treated as palatals, but the latter group remained as alveolars.
3. A distinction between and .
4. Preservation of the checked tone (traditional Chinese: 入聲; simplified Chinese: 入声; pinyin: rùshēng). Although how it was to be realized was not specifically detailed in the original dictionary, it was often pronounced with a final glottal stop, as in Lower Yangtze Mandarin varieties such as the Nanjing dialect.

The actual phonetic values of these tones were not prescribed in the 1919 edition of the Dictionary of National Pronunciation. Although various proposals of merging values from different areas of China were raised, the de facto standard was to use the tonal system of Beijing, and to simply read the entering tone (which the Beijing dialect lacked as a distinctive tone) as a shortened departing tone, falling in nature, as shown from sets of gramophone recordings of Wang Pu, a member of the Commission, and of noted linguist Yuen Ren Chao.