Speech across the menstrual cycle: a replication and extension study.

Area of Science:

• Speech Science
• Linguistics
• Endocrinology
• Psycholinguistics

Background:

• Voice onset time (VOT) is a crucial temporal speech feature influencing production and perception.
• Previous research indicated sex differences and menstrual cycle effects on VOT in natural speech.
• The role of hormonal fluctuations on speech timing requires further investigation, particularly in controlled paradigms.

Purpose of the Study:

• To replicate and extend previous findings on sex differences and menstrual cycle effects on VOT.
• To investigate the impact of hormonal phases (low vs. high estrogen and progesterone) on VOT in a speeded syllable repetition task.
• To examine how hormonal changes modulate sex-specific VOT patterns.

Main Methods:

• VOT measurements were collected for 6 English plosives (/p, b, t, d, k, g/) from 15 women and 20 men (aged 20-25).
• Women were tested during two menstrual cycle phases: Days 2-5 (low estrogen and progesterone/low-EP) and Days 18-25 (high estrogen and progesterone/high-EP).
• Men were tested once; data analyzed for interactions between menstrual cycle phase, voicing, and sex.

Main Results:

• A significant interaction between menstrual cycle phase and voicing was found (P<0.02).
• At the high-EP phase, voiced plosives had shorter VOT, and voiceless plosives had longer VOT, enhancing their distinction.
• Women at high-EP showed longer VOT for voiceless plosives than men, indicating amplified sex differences in this phase.

Conclusions:

• Activational ovarian hormones play a significant role in regulating temporal speech features.
• Hormonal fluctuations during the menstrual cycle impact VOT, affecting the perception of speech sounds.
• The findings extend previous research by demonstrating hormonal influences on VOT in both natural speech and speeded tasks.