Women's voice pitch lowers after pregnancy

Abstract

Women's voice pitch (the perceptual correlate of fundamental frequency, F0) varies across the menstrual cycle and lowers after menopause, and may represent a putative signal of women's fertility and reproductive age. Yet, despite dramatic changes in women's sex hormone levels and bodies during and after pregnancy, previous between-subject and case studies have not found systematic changes in F0 due to pregnancy. Here, we tracked withinindividual variation in 20 mothers' voices during their first pregnancy, as well as up to 5 years before conception and 5 years postpartum. Voice recordings from 20 age-matched nulliparous women were measured as a control. Linear Mixed Models indicated that F0 mean, range and variation changed significantly following pregnancy in mothers, controlling for age at time of recording, whereas we did not observe any F0 changes across corresponding timeframes in our sample of nulliparous controls. Mothers' voices became significantly lower-pitched and more monotonous during the first year postpartum compared to during pregnancy or before. These F0 parameters did not decrease within-individuals over a 5-year period prior to conception above and beyond the effects of ageing. Although voice pitch decreased following pregnancy, mothers' F0 parameters reverted after the first year postpartum, approaching pre-pregnancy levels. Our results demonstrate that pregnancy has a transient and perceptually salient masculinizing effect on women's voices.

Human vocal behavior within competitive and courtship contexts and its relation to mating success

“…Concerning impressions of the size-related feature, listeners regularly associate deeper voice pitch to larger and taller individuals, and conversely, higher voice pitch to thinner and smaller individuals (Pisanski & Rendall 2011;Rendall et al 2007); despite this, vocal features explain little variation in body size (Pisanski et al 2014). Although voice pitch and its resonant frequencies signal little information on the latter, it has been suggested that they could rather be a reliable signal of hormonal quality; e.g., lower voice pitch in men correlated to circulating testosterone levels (Evans et al 2008) or a signal of fertility in women (Feinberg et al 2006;Pisanski, Bhardwaj & Reby 2018). Morton (1977) first suggested that in many birds and mammal species, a common structural convergence of acoustic features exists where low-frequency sounds are used in "hostile" and "harsh" contexts; conversely, higher-frequency sounds are used when "frightened" or "approaching in a friendly manner".…”

Voice in pregnancy context

“…Din momentul concepției și până la naștere corpul femeii suferă modificări semnificative atât la nivel fiziologic cât și metabolic și anatomic. Unele schimbări pot dura chiar și după naștere (Pisanski, 2018) cât și pe perioada alăptării (Emerich, 2001a).…”

Untitled

“…Keywords: pregnancy -speaking voice -evaluation -therapeutic interventionphonotrauma Delimitarea/circumscrierea temei Din momentul concepției și până la naștere corpul femeii suferă modificări semnificative atât la nivel fiziologic cât și metabolic și anatomic. Unele schimbări pot dura chiar și după naștere (Pisanski, 2018) cât și pe perioada alăptării (Emerich, 2001a).…”