Research

Controlling pitch for prosody: Sensorimotor adaptation in linguistically meaningful contexts

A speaker must control the pitch of their voice while they speak to express meaning. We've learned a lot about how people control pitch by observing how they correct pitch errors during a sustained vowel like, "aaaaaaah." But a sustained vowel lacks meaning and so doesn't quite capture how speakers use pitch to communicate. When a pitch error changes the meaning of a sentence, do speakers respond more strongly? Nope. In this study, speakers responded to pitch errors in the same way, regardless of how much it disrupted the meaning they intended to express.

Dahl, K. L.,  Díaz Cádiz, M., & Stepp, C. E. (2023). Controlling pitch for prosody: Sensorimotor adaptation in linguistically meaninigful contexts. The 15th International Conference on Advances in Quantitative Laryngology, Voice, and Speech Research. 1 April 2023. Phoenix, AZ.

Effects of cognitive stress on voice acoustics in individuals with hyperfunctional voice disorders

Hyperfunctional voice disorders (HVDs) are the most common type of voice impairment, yet we don't quite understand why some people develop it. Could it be associated with autonomic dysfunction, which is more prevalent among those with HVDs? We used cognitive stress to induce autonomic arousal in adult speakers with and without HVDs. We expected those with HVDs would experience greater changes in voice acoustics than those without, due to underlying autonomic dysfunction. But they did not! 

Dahl, K. L. & Stepp, C. E. (2023). Effects of cognitive load on voice acoustics in individuals with hyperfunctional voice disorders. American Journal of Speech-Language Pathology, 32(1), 264-274, doi.org/10.1044/2022_AJSLP-22-00204.

Dahl, K. L. & Stepp, C. E. (2022). Effects of cognitive load on voice acoustics in individuals with hyperfunctional voice disorders. Voice Foundation Symposium, Philadelphia, PA. 1-5 June 2022.

Voice and speech changes in transmasculine individuals following circumlaryngeal massage and laryngeal reposturing

Voice is an important means of expressing gender for many transmasculine people. Gender-affirming hormone treatment with testosterone (T) can lead to voice changes, but not for everyone. And not all transmasculine people take T. So we need non-hormonal options for voice care for those who want a more masculine-sounding voice. Could laryngeal manipulation approaches be such an option? For some folks, yes! After a single session, most transmasculine speakers saw changes in their pitch, the position of their larynx, and how masculine their voice sounded to others. 

Here's a short read from Inside Sargent—an interview with BU speech-language pathology alum Felicia François, who completed part of this project for a master's thesis.

Dahl, K. L., François, F. A., Buckley, D. P., & Stepp, C. E. (In press). Voice and speech changes in transmasculine individuals following circumlaryngeal massage and laryngeal reposturing. American Journal of Speech-Language Pathology, 31(3), 1368-1382. https://doi.org/10.1044/2022_AJSLP-21-00245

Graph of two frequency spectra showing differences between the original voice recording and the recording transmitted via a telepractice platform

Reliability and accuracy of expert auditory-perceptual evaluation of voice via telepractice platforms

Telepractice platforms substantially change the acoustics of a patient's voice. So can voice clinicians trust what they hear when listening to a patient by telepractice? They can! Speech pathologists and laryngologists (ENTs) evaluated speakers with a variety of voice disorders as reliably and accurately by telepractice as in person. Expert clinicians seem to distinguish between the "noise" of platforms like Zoom and the "noise" of a voice disorder.

Here's a quick write-up on this project from Inside Sargent magazine.

Dahl, K. L., Weerathunge, H. R., Buckley, D. P., Dolling, A. S., Díaz-Cadiz. M., Tracy, L. F., & Stepp, C. E. (2021). Reliability and accuracy of expert auditory-perceptual evaluation of voice via telepractice platforms. American Journal of Speech-Language Pathology, 30(6), 2446-2455. https://doi.org/10.1044/2021_AJSLP-21-00091

A person holding a card with sentence with four color terms, each printed in a colored ink that does not match the word. The printed sentence reads, "Then our pal gave blue, pink, green, and red new posters to us." A speech bubble shows that the person has read the sentence aloud, but has stated the color of the ink for each word instead of the color word printed.

Changes in relative fundamental frequency under increased cognitive load in individuals with typical voices

Cognitive stress arouses the autonomic nervous system (ANS). When speaking under ANS arousal, our voice quality changes and laryngeal muscle activity increases. Are the changes in the sound of our voice related to this increased muscle activity? Yep! Speakers without voice disorders may tense up their laryngeal muscles in a specific pattern when speaking under cognitive stress. It remains to be seen if this is also true of speakers with voice disorders. Stay tuned!

Dahl, K. L., & Stepp, C. E. (2021). Changes in relative fundamental frequency under increased cognitive load in individuals with healthy voices. Journal of Speech, Language, and Hearing Research, 64(4), 1189–1196. https://doi.org/10.1044/2021_JSLHR-20-00134

A four-panel plot showing the relationships between voice femininity ratings and four acoustic measures of voice and speech.

Acoustic features of transfeminine voices and perceptions of voice femininity

Many features of voice and speech contribute to the perception of gender and femininity. Are certain features particularly important in determining how the voices of transgender women are perceived? Seems so! Trans women with higher pitched and louder voices were perceived as more feminine by both unfamiliar listeners and by trans women themselves. Trans women rated their voices as less feminine than did listeners, revealing the importance of self-perceptions in this population.

Dahl, K. L., & Mahler, L. A. (2020). Acoustic features of transfeminine voices and perceptions of voice femininity. Journal of Voice, 34(6), 961.e19-961.e26. https://doi.org/10.1016/j.jvoice.2019.05.012