Differences in glottal opening pattern between Tokyo and Osaka dialect speakers: factors contributing to vowel...

Area of Science:

• Phonetics
• Linguistics
• Acoustic phonetics

Background:

• High vowels /i/, /u/ in Japanese are often devoiced between voiceless consonants.
• Vowel devoicing occurs frequently in Eastern Japanese dialects (e.g., Tokyo) but less in Western dialects (e.g., Osaka).
• Previous research suggests more careful consonant articulation in Eastern dialects contributes to higher vowel devoicing frequency.

Purpose of the Study:

• To investigate differences in glottal opening gestures of voiceless consonants between Tokyo and Osaka Japanese speakers.
• To determine if articulatory differences in voiceless consonants explain the dialectal variation in vowel devoicing.

Main Methods:

• Acoustic analysis of voiceless consonant articulation (glottal opening) in Tokyo and Osaka speakers.
• Comparison of glottal gestures in voiced and devoiced contexts for specific consonants like /k/.

Main Results:

• Tokyo speakers exhibited significantly longer glottal opening durations for /k/ in voiced syllables compared to Osaka speakers.
• For Tokyo speakers, devoiced syllables showed significantly larger glottal opening duration and maximum size for /k/ compared to voiced syllables.
• The observed glottal gestures exceeded a simple additive model of adjacent consonant gestures, suggesting interaction.

Conclusions:

• Articulatory differences in glottal gestures for voiceless consonants, particularly /k/, distinguish Tokyo and Osaka Japanese speakers.
• Enhanced glottal opening in Tokyo speakers may contribute to the higher frequency of vowel devoicing observed in their dialect.
• Airflow dynamics during consonant release appear to influence vowel length and potentially devoicing.