Japanese phonetic notation using the English alphabet requires notating Japanese phonetics with letters by following the relationship between letters and sounds used in English notation methods. For example, the word seito (students) is notated as "seh-eh-toh".
Hepburn Romanization is generally used when notating Japanese into letters. While Hepburn consonants follow the English notation method, the vowels do not, so it is difficult to know how to pronounce romanized Japanese words without knowledge of the Hepburn system. For this reason, we propose a Japanese phonetic notation system that allows both vowels and consonants to be read correctly by native English speakers.
For this purpose, two research studies were conducted. The first was a dictation study in which native English speakers who did not know Japanese listened to spoken Japanese and wrote down the words using the English alphabet. The second was an oral reading study in which the participants read out each candidate for the phonetic notation method that had been narrowed down through the dictation study, identifying the notation that was most likely to be read the way it sounds in Japanese.
The main characteristics of this phonetic notation are detailed from (a) to (e).
(a) The mora boundaries are notated with "-".
(b) Vowels [a, i, u, e, o] are notated as "ah, ee, woo, eh, oh" respectively.
(c) Long vowels are notated with one of the following in accordance with the preceding mora vowels: "ah, ee, woo, eh, oh".
(d) With moraic obstruents, a "-" will be inserted between two consonants, such as in "kot-chee" (kotchi, here).
(e) With moraic nasals, a "-" will be inserted before and after the words: for example, "hah-m-boo-n" (hambun, half).