The Mora is More Hypothesis

The Japanese Mora has been defined as a unit of equal duration relative to other mora in the same utterance where a heavy syllable has two, and a short syllable has one. The issue of relative equal duration has been questioned by some and supported by others. The ‘Mora is More’ Hypotheses accounts for the number of mora in a syllable by measuring the duration of the syllable and comparing it against a relative durational ruler that is marked off in units of the relative norms for a mora at a given speech tempo. Each syllable has at least one mora. When a syllable measures more than a relative norm, an additional mora is perceived. An experiment was conducted to ascertain perceivable thresholds which would match the native speaker’s ability to account for additional morae. Results showed that syllables that exceeded 1.453 times the relative norm were perceived as having an additional mora. There was a grey window of plus or minus .13 indicating syllables measuring less than 1.323 were perceived as containing one mora, and those which measure more than 1.583 were perceived as containing two morae. Syllables measuring within the grey window could be perceived either as one mora or two morae. These thresholds when tested showed an accuracy rate of 96% of accounting for morae. Closer examination of the error rate found those syllables to be within the grey window, thus indicating no real failure of thresholds. Implications include L2 acquisition and automated speech recognition.

Thesis Author: Bangerter, Grant W.

Year Completed: 1998

Committee Members: Alan Manning, Melvin J. Luthy

Thesis Chair: John S. Robertson

Thesis Award: Outstanding Linguistics Thesis