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Gender DysphoriaB6702021001262NCT05204732

Acoustic and Perceptual Effects of Intonation Training in Gender Diverse People

A study testing Intonation training in people with Gender Dysphoria, run by University Ghent at 1 site in Belgium.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The aim of this project is to investigate the short- and the longer-term effect of intonation training on vocal characteristics, listener perceptions and patient related outcome measures (PROMS) in gender diverse people using a randomized sham-controlled trial. Read more about this study

Who is it for?
Ages 18 to 60 yearsHealthy volunteers can take part
Conditions the study is for
Gender Dysphoria
What is being tested?
Intonation training
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
55 participants
Where
1 siteBelgium
Study dates
30 Mar 2022to 31 Mar 2025
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 60 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Normal hearing (using ISO standard audiometry)
  • Native Dutch speaker

Who cannot join

  • A history of neurological disorders
  • Previous phonosurgery or speech therapy
  • Vocal pathology (using videolaryngostroboscopy)
  • Smokers.

Trial locations and contacts

1 site in 1 country.

Belgium1 site
  • Ghent University

    Ghent, East Flanders, 9000

Other trials in Belgium

About this study

The aim of this project is to investigate the short- and the longer-term effect of intonation training on vocal characteristics, listener perceptions and patient related outcome measures (PROMS) in gender diverse people using a randomized sham-controlled trial.

Read the detailed description

Background and Problem Statement. Speech training in gender diverse individuals focuses on aspects of communication that strongly influence gender perception. Findings from the literature suggest that a listener's gender perception is determined not only by pitch, but also by other components such as intonation. However, the nature and extent of pitch changes required to alter gender perception are not known. In speech therapy, intonation training is frequently used for speech feminization. However, empirical evidence for this is lacking.

Research questions and/or hypotheses Thisresearch investigates the short- and long-term effects of intonation training on acoustic voice characteristics, gender perception and findings of gender-diverse individuals using a randomized sham-controlled trial (RCT). Based on findings from the literature, (a) gender-congruent values are expected for intonation parameters, in addition (b) assessments of gender that fit the gender identity of the person and (c) an improvement in self-assessment after intonation training in the short and long term. This study will lead to new insights into the relationship between intonation and gender perception and makes an important contribution to the evidence for the use of intonation training.

Research Protocol An RCT will be used. Gender diverse individuals will be recruited through the Ghent University Hospital. Inclusion criteria are: diagnosis of gender dysphoria established by the multidisciplinary gender team, age between 18 and 60 years, normal hearing and Dutch mother tongue. Taking into account the expertise of the research group and the low-threshold recruitment through the gender clinic of UZ Gent, a total of n=20 participants is a very feasible number. Subjects will be randomly assigned to the experimental (intonation training) or control group (receiving a placebo intervention). Randomization will be stratified by age group and baseline speaking fundamental frequency. The experimental group will receive 4 weeks (1h/week) of intonation training with a pre- and post-voice assessment and a follow-up assessment after 8 weeks. The control group will receive sham therapy at a similar duration and frequency, also with a pre- and post-measurement and a follow-up assessment after 8 weeks. The control group will receive 4 more weeks (1 hour/week) of intonation training with a post measurement (due to ethical reasons). The multidimensional speech assessments will be blinded and completed and well-defined training programs will be used. The primary outcome measures are: acoustic intonation parameters, gender perception by listeners and self-assessment and client satisfaction. Linear mixed models with post-hoc pairwise comparisons will be used to analyze the evolution of continuous data within and between groups. ICC models and Cohen's kappa will be used to analyze inter- and intra rater reliability.

Being tested
Intonation training, Sham therapy + intonation training
Keywords
gender, gender perception, intonation, prosody, speech, gender diverse
Medical subject headings
Gender Dysphoria, Coitus, Speech

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Intonation trainingOther

    The participants will receive intonation training (1h/week) for four weeks, aiming for more gender congruent intonation patterns.

  • Sham therapy + intonation trainingOther

    The participants will first receive four weeks of sham therapy (with no expected effect on speech), during which information on voice functioning, voice surgery, voice hygiene, and transgender health care will be provided. In addition, during sham therapy, active intervention will be given around nonverbal communication. After four weeks of sham therapy, for ethical reasons, subjects in this group will also receive four weeks of intonation training (aiming for more gender congruent intonation patterns).

Study groups in NCT05204732
Study groupRoleWhat they receive
Experimental groupExperimental* Speech training: 4 times 1 hour of intonation training for 4 weeks * Standard voice assessment (voice recording, VAS, questionnaire(s)) (1 premeasurement and 2 postmeasurements)
Receives: Other: Intonation training
Control groupSham comparator* Speech training: : 4 times 1 hour sham therapy (info sessions + active intervention non-verbal communication) during 4 weeks + 4 times 1 hour intonation training during 4 weeks * Standard voice assessment (voice recording, VAS, questionnaire(s)) (1 premeasurement and 3 postmeasurements)
Receives: Other: Sham therapy + intonation training

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in general intonation shift (Hz and ERB)

    The general intonation shift is the mean size of the general increase or decrease of the fundamental frequency during the utterance. For the calculation of this parameter, the first and last vowel of the sentence were selected and the fo of the vowels were determined. Subsequently, the general intonation shift was calculated as the difference between start and end fo. Based on the size of this difference, the general intonation shift was categorized as an upward, downward or flat intonation shift. A difference smaller than 1.570884399 ERB was considered as a flat intonation shift. Finally, the percentage of upward, downward and flat intonation shifts could be determined.

    Measured: baseline (before treatment) - at the end of the treatment period (after 4 weeks) - 4 (and 8) weeks after the end of the treatment period (after 8 (and 12) weeks (each measurement +/- 20 min.)

  2. Change in final intonation shift (Hz and ERB)

    The Final intonation shift indicates the average size of the upward or downward intonation shift at the end of the utterance. This parameter was calculated as the difference between the fo at the beginning of the final rise or drop and the fo at the end. The beginning was located on the last stressed vowel and the end of the final rise or drop was located on the last unstressed vowel. In case that the utterance ended with a stressed vowel, the intonation shift was derived from the difference in fo within this vowel.

    Measured: baseline (before treatment) - at the end of the treatment period (after 4 weeks) - 4 (and 8) weeks after the end of the treatment period (after 8 (and 12) weeks (each measurement +/- 20 min.)

  3. Change in general pitch range (Hz and ERB)

    This parameter was calculated as the difference between the minimum (5th percentile) and the maximum fo (95th percentile) of the utterance. For this calculation the "Intonantion and stress trajectory" script was used (Corthals, 2019a; Van Borsel, Vandaele, \& Corthals, 2013).

    Measured: baseline (before treatment) - at the end of the treatment period (after 4 weeks) - 4 (and 8) weeks after the end of the treatment period (after 8 (and 12) weeks (each measurement +/- 20 min.)

  4. Change in pitch variation index (Hz/s and ERB/s)

    This parameter was determined by the sum of the absolute value of all pitch changes during the utterance between percentile 5 and 95 divided by the total duration of the utterance. The pitch variation index reflects the size and speed of the intonation maneuvers. For this parameter the script "Intonation and stress trajectory" was used (Corthals, 2019a; Van Borsel, Vandaele, \& Corthals, 2013).

    Measured: baseline (before treatment) - at the end of the treatment period (after 4 weeks) - 4 (and 8) weeks after the end of the treatment period (after 8 (and 12) weeks (each measurement +/- 20 min.)

  5. Gender perception of the voice

    A listening experiment with femininity ratings using a visual analogue scale (VAS: very feminine - neutral - very masculine).

    Measured: During a listening experiment (+/- 40 minutes).

  6. Change in patient's satisfaction with their voice - VAS

    Visual analoge scales investigating the client's satisfaction of the therapy and psychosocial functioning:

    examples:

    1. My speech fits who I am (don't agree at all - neutral - completely agree)
    2. How masculine/feminine do you sound while speaking? (very masculine - gender ambiguous (neutral) - very feminine)
    3. While speaking, there is a wide variation of my pitch. (don't agree at all - neutral - completely agree) (3) I sound more feminine/male/neutral compared to before the training period. (don't agree at all - neutral - completely agree)
    4. After the training period, my pitch range increased (I can produce higher and/or lower tones). (don't agree at all - neutral - completely agree))

    Measured: baseline (before treatment) - at the end of the treatment period (after 4 weeks) - 4 (and 8) weeks after the end of the treatment period (after 8 (and 12) weeks (each measurement +/- 5 min.)

  7. Change in patient's satisfaction with their voice - TWVQ

    Trans Women Voice Questionnaire: 30 questions investigating trans women's experiences with their voice (1 = never or seldom; 2 = sometimes; 3 = often; 4 = usual or always). The score can range from 30 to 120. A lower score indicates higher satisfaction with the voice.

    Measured: baseline (before treatment) - at the end of the treatment period (after 4 weeks) - 4 (and 8) weeks after the end of the treatment period (after 8 (and 12) weeks (each measurement +/- 5 min.)

  8. Change in patient's satisfaction with their voice - VHI

    Voice Handicap Index: 30 questions investigating the impact of voice on the quality of life (0 = never; 1 = almost never; 2 = sometimes; 3 = almost always; 4 = always) . The score can range from 30 to 120. A lower score indicates higher satisfaction with the voice.

    Measured: baseline (before treatment) - at the end of the treatment period (after 4 weeks) - 4 (and 8) weeks after the end of the treatment period (after 8 (and 12) weeks (each measurement +/- 5 min.)

Secondary outcomes (6)
  1. Change in speech fundamental frequency (SFF)

    median speech fundamental frequency (SFF)

    Measured: baseline (before treatment) - at the end of the treatment period (after 4 weeks) - 4 (and 8) weeks after the end of the treatment period (after 8 (and 12) weeks (each measurement +/- 5 min.)

  2. Change in formant frequency 1 (F1)

    F1 of the vowels /a/, /i/ and /u/

    Measured: baseline (before treatment) - at the end of the treatment period (after 4 weeks) - 4 (and 8) weeks after the end of the treatment period (after 8 (and 12) weeks (each measurement +/- 5 min.)

  3. Change in formant frequency 2 (F2)

    F2 of the vowels /a/, /i/ and /u/

    Measured: baseline (before treatment) - at the end of the treatment period (after 4 weeks) - 4 (and 8) weeks after the end of the treatment period (after 8 (and 12) weeks (each measurement +/- 5 min.)

  4. Change in formant frequency 3 (F3)

    F3 of the vowels /a/, /i/ and /u/

    Measured: baseline (before treatment) - at the end of the treatment period (after 4 weeks) - 4 (and 8) weeks after the end of the treatment period (after 8 (and 12) weeks (each measurement +/- 5 min.)

  5. Change in formant frequency 4 (F4)

    F4 of the vowels /a/, /i/ and /u/

    Measured: baseline (before treatment) - at the end of the treatment period (after 4 weeks) - 4 (and 8) weeks after the end of the treatment period (after 8 (and 12) weeks (each measurement +/- 5 min.)

  6. Change in formant frequency 5 (F5)

    F5 of the vowels /a/, /i/ and /u/

    Measured: baseline (before treatment) - at the end of the treatment period (after 4 weeks) - 4 (and 8) weeks after the end of the treatment period (after 8 (and 12) weeks (each measurement +/- 5 min.)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted24 Jan 2022
  2. Study start30 Mar 2022
  3. Primary completion31 Dec 2024
  4. Study completion31 Mar 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Double blind
Who is masked
Participant, Investigator
Enrolment
55 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05204732
Sponsor's protocol ID
BC-11303
Acronym
B6702021001262
Status last verified
Apr 2025
First submitted
19 Nov 2021
Last updated
17 Apr 2025
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing Intonation training in people with Gender Dysphoria, run by University Ghent at 1 site in Belgium.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 17 Apr 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in general intonation shift (Hz and ERB) (time frame: baseline (before treatment) - at the end of the treatment period (after 4 weeks) - 4 (and 8) weeks after the end of the treatment period (after 8 (and 12) weeks (each measurement +/- 20 min.)). The study lists 8 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Apr 2025.

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