Way back in February of 2023, we published an article about vocal surgeries to raise or lower pitch. One of the surgery types is glottoplasty: changing the length or tension (or both!) of the vocal cords.
If you shorten the vocal cords or make them tighter, you increase tension on them and voice pitch goes higher. If you lengthen or loosen the vocal cords, tension and pitch drop. It’s kind of like tuning a stringed instrument. The tighter you pull the string, the higher the sound the string produces when it vibrates. Glottoplasties are frequently used in transgender medicine to raise the pitch of the voice by changing how fast the vocal cords vibrate when air passes through them.
There are several different ways to do a glottoplasty. We thought we’d do a review of what we currently know about the various options. All of these surgeries are done under general anesthesia and through the mouth, so no incisions are made in the neck: no visible scars!
Wendler Glottoplasty:
A laser is used to take away tissue from the front third of the vocal cords (towards the front of your neck.) Then the cords are sewn together. The result is the cords have less total vibrating mass and less length front to back, and may be tighter across the width of the voice box. It is often called a web glottoplasty because the front of the cords are joined together, forming a web of tissue.
Modified Wendler Glottoplasty:
The main difference in a modified Wendler is that the vocal cords are joined together with something other than sutures (like surgical glue.) The vocal cords themselves may or may not have tissue removed or altered. The vocal cords may be altered by either removing mass or increasing tightness through injecting a surgical filler. This Wendler version may take less surgical time to complete and have fewer risks of complications because there are no sutures to worry about.
Laser Reduction Glottoplasty (LRG):
A laser is used to cut an incision on the tops of the cords, starting at the back of the throat rather than the front. Then, tissue inside the vocal folds – muscle and ligament – is removed. Then the incisions are sutured closed, but the two vocal cords themselves are not sutured to each other. The result is the vocal folds have less total vibrating mass and are pulled away from the center opening slightly, creating more tension to the cords. (Koçak)
Several of these studies had images taken during surgery. To us, vocal cords look a heck of a lot like fortune cookies. So here’s our (clumsy!) visual interpretation of the surgical procedures for you:
Where Are The Vocal Cords In The Body?
Some terms to know:
Fundamental Frequency: (F0) this is the rate at which the vocal cords vibrate. It is expressed in Hertz, which is a measurement of vibration cycles per second. May also be called Foundational Frequency.
Gendering of Fundamental Frequency:
- Voices below 150 Hz are typically perceived as belonging to bodies that are testosterone-dominant.
- Voices above 160 Hz are typically perceived as belonging to bodies that are estrogen-dominant. (Anderson)
These ranges aren’t set in stone. There are many factors which contribute to a gendered perception of voice. These aren’t even the only measurements used to describe the perceived gender of a voice–but, we’re focusing on fundamental/foundational frequency today. Gendering of voices changes incredibly across cultures and communities. One article wrote “However, in our experience, voices are only consistently judged as feminine by patients and providers once a pitch of 190 Hz is reached.” (Yilmaz 2023)
We’re not fans of limiting gender terminology to “masculine” or “feminine,” but at times we reflect language in the source studies:
In a study of transgender speakers where recorded voices were evaluated for gender by both the speakers and a group of listeners, here’s how they grouped perceived gender by pitch of the voices:
- The femininely-rated voices were in a range of 150-181 Hz, with a mean of 165 Hz.
- The masculinely-rated voices were in a range of 106 – 127 Hz, with a mean of 116 Hz. (Dahl)
What About Voice Therapy?
Voice therapy is often recommended before and after surgical interventions. Recent studies indicate that voice therapy contributes to an average increase of 30 Hz in spoken reading ranges. This may not be satisfactory for many people and they may choose to pursue surgical options. (D’haeseleer)
One study (d’Haesseler) specifically looked at self-assessed satisfaction scores of the patients who received voice therapy after surgery compared to those who did not. This study note that while self-assessment of perceived femininity scores were higher in women who obtained voice therapy after surgery, “women in this study seemed equally satisfied after glottoplasty with or without voice therapy.”
So generally, what we’re looking at in comparing the surgical methods are what were the starting and ending fundamental frequencies of the participants and how much did fundamental frequency change from each type of surgery?
Notes: Voice pitch changes tend to be greatest shortly after surgery and decrease over time. We’ve omitted discussions of voice evaluations immediately after surgery when it has been included in the studies below.
Evaluating the Voice
The studies we reviewed used a variety of tools to measure how people felt about their voices and the changes they achieved. Here’s descriptions of those tools:
CAPE-V Pitch Score: this score attempts to describe the difference between actual voice pitch and desired voice pitch. Higher scores indicate a larger difference between perceived pitch and desired pitch. (Husain)
TWVQ – the Trans Woman Voice Questionnaire. The TWVQ measures a person’s self-assessment of their voice’s match with gendered expectations. A lower score indicates a greater match to expectations. A copy of the TWVQ in multiple languages can be obtained via the La Trobe University Communication Clinic.
TVQ – the Transsexual Voice Questionnaire for Male-to-Female Transsexuals. Thirty questions about perceptions about voice with a 4-point range describing frequency (1 = never; 4 = always). For example, “I feel my voice does not reflect the true me.” Lower scores indicate fewer difficulties with voice. (Dakacis)
VHI – Voice Handicap Index – self-administered questionnaire that measures the impact of voice on psychosocial well-being. (VHI)
VRQOL – Voice-Related Quality of Life Measure. A self-administered questionnaire measuring physical and social-emotional impacts of voice. It contains 10 questions that are ranked 1 – 5 with 1 meaning no impact and 5 indicating worst possible impact. Answers are scored by an algorithm with results between 0 (very bad negative impacts of voice on quality of life) to 100 (excellent quality of life.) An image of the VRQOL can be seen here.
VAS Voice – Visual Analogue Scale of Voice Quality – a four item questionnaire asking patients to rate on a scale of 0 (not at all) – 10 (worst possible):
- How much does your voice bother you?
- My voice problem makes me feel upset.
- My voice proble makes it difficult to participate in my normal functions.
- My voice problem causes strain, discomfort, or increased effort to speak. (Naunheim)
Other procedures mentioned in the studies:
Cricothyroid Approximation Surgery (CTA): moves the cricoid cartilage closer to the thyroid cartilage. This surgery stretches the vocal cords, making them longer and tighter. The cricoid cartilage is a ring of cartilage that connects the thyroid cartilage to the top of the trachea. The thyroid cartilage is at the top of the larynx. We include anatomical images in our earlier article on surgeries to change pitch.
Math and Statistics Terms:
Average, Mean, and Median – not all of the articles we’re referencing reported results using a mean. So here’s a quick statistics lesson:
- Mean and Average are the same thing: add up all the numbers in the data set and divide by the number of values in the set.
- Example number set: 3, 6, 13, 27, 31, 38, 42
- The average is the sum of the numbers (160) divided by how many numbers there are (7) = 22.87.
- The Median is the middle value in a set of numbers when they are in order from smallest to largest. In our example set, that number is 27.
- In our example, it’s pretty obvious that the mean and the median are different. It isn’t always obvious.
Enough Already, Let’s Look At The STUDIES:
Note: we did not do an exhaustive literature review to obtain these studies. We make no claims to a broad analysis.
However, there is a meta-analysis of glottoplasty studies published in 2023. This study found that the mean difference between fundamental frequency before and after glottoplasty was 78.49 Hz with a range of change between 20 to 112 Hz. (Aires, d’Haesseler, Song, Anderson)
Takeaways:
All of these studies had very few participants, so we can’t make any conclusions about how likely the results of these patients are to any other individual thinking about vocal surgeries.
If we’re defining “successful procedure” as “greatest increase in foundational frequency,” a modified Wendler or a combination of LRG and Wendler appear to be the winners.
All approaches resulted in higher pitch voices. All studies except one of the Wendler-alone achieved final voice pitches above 190 Hz.
It appears that modified Wendler glottoplasties were able to achieve the highest change in voice foundational frequency. The two studies reporting on modified Wendler techinques achieved the highest pitch outcomes (238 and 245.9 Hz.
A meta-analysis of glottoplasty studies found a mean frequency change of 78.49 Hz. Starting voice frequency ranges were between 116 – 158.6 Hz, and post-operative ranges were between 169.4 and 244 Hz.
Where patient satisfaction was measured, the LRG procedure done without any other procedures had the lowest satisfaction scores.
Other Things To Think About:
Risks of these procedures include:
- Pitch instability
- Changes to or poor voice quality
- Swelling in the vocal cords that can affect voice quality and breathing. (Aires)
Following after-care and vocal rest recommendations after surgery may lower risk of complications.
Here’s a visual of the mean frequency range increased in each study. The colored bars start on the left with the average voice frequency before glottoplasty, and end on the right with the average voice pitch frequency after surgery. The length of the bar is the amount of change between starting and ending frequency.
And Here’s Information From Each Study We Looked At
Classic Wendler Glottoplasty: 2 studies included
- Study 1:
- Average voice frequency prior to surgery: 135.8 Hz
- Average voice frequency after surgery: 206.3 Hz
- That seems pretty darn good.
- Patient satisfaction notes: no significant difference; overall, patients were satisfied with the results.
- Study 2:
- Average voice frequency prior to surgery: 128.02 Hz
- Average voice frequency after surgery: 161.21 Hz
- Not as big a gain as the first study.
- Patients who had both procedure and voice therapy after procedure had higher satisfaction scores.
Modified Wendler Glottoplasty: 3 studies included
- Study 1:
- Average voice frequency prior to surgery: 136.1 Hz
- Average voice frequency after surgery: 245.9 Hz
- WOWZA!
- Limited patient satisfaction data available, but data seems to indicate a greater self-perceived voice & gender match
- Study 2:
- Average voice frequency prior to surgery: 151.5 Hz
- Average voice frequency after surgery: 212.9 Hz
- Another: wow, that looks like a pretty large change.
- Patient satisfaction: All patients had a significant increase in self-perceived voice & gender match.
- Study 3:
- Average voice frequency prior to surgery: 127.8 Hz
- Average voice frequency after surgery: 238 Hz
- Another WOWZA!
- Patient satisfaction: Not noted
Laser Reduction Glottoplasty (LRG): 2 studies
- Study 1:
- Average voice frequency prior to surgery: 158.33 Hz
- Average voice frequency after surgery: 203.50 Hz
- Results well within “female” voice frequency range.
- All patients reported satisfactory outcomes and perception of voice gender.
- Study 2:
- Average voice frequency prior to surgery: 132 Hz
- Average voice frequency after surgery: 198 Hz
- Results well within “female” voice frequency range.
- Nine patients (out of 28) were not satisfied with achieved change.
And, a study of LRG after Wendler Glottoplasty:
- Average voice frequency prior to surgery: 146 Hz
- Average voice frequency after surgery: 215 Hz
- Another WOWZA for the high-pitched results.
- Patient gratification score of 100% after 2nd procedure.
Want to see the data in a different form? Download our study matrix chart.
Citations and References
(these aren’t in perfect order, nor are they all in the same format – we’ll get to it, time allowing)
Rogalska M, Zielinski M, Antkowiak L, Kasperczuk A, Misiolek M. Impact of Wendler glottoplasty on acoustic measures and quality of voice in transgender women: a systematic review and meta-analysis. Eur Arch Otorhinolaryngol. 2024 Jul;281(7):3345-3360. doi: 10.1007/s00405-024-08486-3. Epub 2024 Feb 5. PMID: 38315177.
Misiołek M, Rogalska M, Zieliński M, Kasperczuk A, Koniewska A. Acoustic outcomes and voice-related quality of life in male-to-female transsexuals undergoing Wendler glottoplasty: a single-centre experience. Endokrynol Pol. 2024;75(2):222-229. doi: 10.5603/ep.98899. Epub 2024 Mar 18. PMID: 38497370.
Rapoport SK, Park C, Varelas EA, Chang J, Brown SK, Kinberg E, Goldberg L, Courey MS. 1-Year Results of Combined Modified Wendler Glottoplasty with Voice Therapy in Transgender Women. Laryngoscope. 2023 Mar;133(3):615-620. doi: 10.1002/lary.30225. Epub 2022 May 30. PMID: 35634734.
Brown SK, Chang J, Hu S, Sivakumar G, Sataluri M, Goldberg L, Courey MS. Addition of Wendler Glottoplasty to Voice Therapy Improves Trans Female Voice Outcomes. Laryngoscope. 2021 Jul;131(7):1588-1593. doi: 10.1002/lary.29050. Epub 2020 Aug 26. PMID: 32846023.
Schwarz K, Fontanari AMV, Schneider MA, Borba Soll BM, da Silva DC, Spritzer PM, Kazumi Yamaguti Dorfman ME, Kuhl G, Costa AB, Cielo CA, Villas Bôas AP, Lobato MIR. Laryngeal surgical treatment in transgender women: A systematic review and meta-analysis. Laryngoscope. 2017 Nov;127(11):2596-2603. doi: 10.1002/lary.26692. Epub 2017 Jul 3. PMID: 28671273.
Song TE, Jiang N. Transgender Phonosurgery: A Systematic Review and Meta-analysis. Otolaryngol Head Neck Surg. 2017 May;156(5):803-808. doi: 10.1177/0194599817697050. Epub 2017 Mar 28. PMID: 28349733.
Jennifer A. Anderson, Pitch Elevation in Trangendered Patients: Anterior Glottic Web Formation Assisted by Temporary Injection Augmentation, Journal of Voice, Volume 28, Issue 6, 2014, Pages 816-821, ISSN 0892-1997, https://doi.org/10.1016/j.jvoice.2014.05.002.
(https://www.sciencedirect.com/science/article/pii/S0892199714000952)
Meister, J., Kühn, H., Shehata-Dieler, W., Hagen, R. and Kleinsasser, N. (2017), Perceptual analysis of the male-to-female transgender voice after glottoplasty—the telephone test. The Laryngoscope, 127: 875-881. https://doi.org/10.1002/lary.26110
Yılmaz, T., Özer, F., & Aydınlı, F. E. (2021). Laser Reduction Glottoplasty for Voice Feminization: Experience on 28 Patients. Annals of Otology, Rhinology & Laryngology, 130(9), 1057–1063. https://doi.org/10.1177/0003489421993728
Yılmaz T. Sequential Wendler Glottoplasty and Laser Reduction Glottoplasty for Voice Feminization. Laryngoscope. 2024 Mar;134(3):1133-1138. doi: 10.1002/lary.30958. Epub 2023 Aug 9. PMID: 37555644.
Koçak I, Akpnar ME, Çakr ZA, Doğan M, Bengisu S, Çelikoyar MM. Laser Reduction Glottoplasty for Managing Androphonia After Failed Cricothyroid Approximation Surgery. Journal of voice. 2010;24(6):758-764. doi:10.1016/j.jvoice.2009.06.004
Solomon Husain, Lauren Campe, Natasha Mirza, Modification of Wendler Glottoplasty for Male to Female Gender Transition, Journal of Voice, 2023, https://doi.org/10.1016/j.jvoice.2023.01.028.
(https://www.sciencedirect.com/science/article/pii/S0892199723000279)
The Voice Handicap Index (VHI)
Barbara H. Jacobson, Alex Johnson, Cynthia Grywalski, Alice Silbergleit, Gary Jacobson, Michael S. Benninger and Craig W. Newman
Naunheim MR, Dai JB, Rubinstein BJ, Goldberg L, Weinberg A, Courey MS. A visual analog scale for patient-reported voice outcomes: The VAS voice. Laryngoscope Investig Otolaryngol. 2019 Dec 17;5(1):90-95. doi: 10.1002/lio2.333. PMID: 32128435; PMCID: PMC7042645.
Dacakis, G., Davies, S., Oates, J. M., Douglas, J. M., & Johnston, J. R. (2013). Transsexual Voice Questionnaire for Male-to-Female Transsexuals [Database record]. Retrieved from PsycTESTS. doi: https://dx.doi.org/10.1037/t28993-000
Dacakis G, Davies S, Oates JM, Douglas JM, Johnston JR. Development and Preliminary Evaluation of the Transsexual Voice Questionnaire for Male-to-Female Transsexuals. Journal of voice. 2013;27(3):312-320. doi:10.1016/j.jvoice.2012.11.005
Norman D. Hogikyan, The Voice-Related Quality of Life (V-RQOL) Measure: History and Ongoing Utility of a Validated Voice Outcomes Instrument, Perspectives on Voice and Voice Disorders, 2004-03-01 14(1): 3-5 doi: 10.1044/vvd14.1.3, https://pubs.asha.org/doi/full/10.1044/vvd14.1.3
