Objective: Acoustic cues to gender stereotyping have been described in the literature, with most studies focussing on fundamental frequency and formant spacing. Physiological measures of gender stereotyping from speech have been less investigated, especially with regard to phonatory airflow. This is surprising in view of the evident fact that, not only size, but also airway, lungs and function are sex dependent.

Methods/ Design: A total of 17 females and 17 males cisgender heterosexual Spanish young adults were recorded while speaking the same phrase portraying different gender roles: the gender of the sex at birth, with (1) and without (2) assuming any gender stereotype; the opposite gender to the sex at birth, with (3) and (4) without stereotyping for the gender; and (5) the gender of the sex at birth, stereotyping for that gender with the aid of a visual cue. These portrayals were recorded in a single sequence, all following the order (1) to (5). Thus, (1) could be used as a perceptual reference to guide subsequent portrayals. All recordings were made in a sound treated portable cabinet using FonaDyn for synchronous recordings of audio and lung volume signals. The former was recorded using the omnidirectional microphone (ECM8000, Behringer, German), placed at 30 cm from the participant’s mouth, while the latter was recorded using the RespTrack system (Columbi computers, Sweden), with the upper and the lower elastic respbands placed around the chest and the abdominal wall, respectively. The sensitivity of the respbands was previously adjusted to equal sensitivity with an isovolume manoeuvre.

Results: Male voices revealed higher phonatory airflows as compared to females when assuming the gender role that match their sex at birth. When males portrayed a female stereotyping of sounding “most feminine as possible”, they increased their phonatory airflow as compared to the gender of the sex at birth. This seems to be a behaviour to assume a stereotype of a breathier voice for the female gender. The reverse was found for female voices. For both sexes, portrayals using visual cues of gender stereotypes (5) rendered the biggest differences between gender and portrayed gender roles.

Conclusions: The study demonstrates that phonatory airflow is not only sex dependent but also gender stereotyped. Stereotypes of masculinity and femininity seem to exaggerate the differences observed in phonatory airflow between sexes, higher phonatory airflow for males as compared to females. Clearly, gender stereotypes can also be depicted from phonatory airflow and breathing behaviours. These results may be relevant, especially with respect to the training of the transgender voice.