1976 Volume 19 Issue 3 Pages 168-172
Interrelationship of loudness sensation among five Japanese vowels was studied with the use of paired comparison method under three conditions.
Under the first condition, the five vowels were pronounced with the same subjective loudness and, consequently, with different intensity.
Under the second condition, the vowels were pronounced with the intensity as equally each other as possible.
Under the third condition, the intensity of the vowels of the first condition was mechanically adjusted to approximately the same level.
All vowels were uttered by a normal male subject at a constant pitch. Thirteen listeners listened to the edited tape through a loudspeaker and judged the loudness difference in every pair on five point scales.
The results of the listening test showed that the order of loudness sensation among the five vowels under the first condition was identical to intensity order, i.e., /A/, /O/, /E/, /U/, /I/, and /A/ was the strongest.
Under the second and the third conditions, on the other hand, the order of loudness sensation was different from intensity order, and /I/ was judged as loudest while /A/ was judged as softest under both conditions.
The results suggest that loudness sensation of vowels is not only related to vowel intensity, but also to some other unknown acoustic factors.