Recently, we had a family ask if we had any information about how ectodermal dysplasia affects the voice. The National Foundation for Ectodermal Dysplasias (NFED) did support a research project in the late 1990s that Kelly Mabry, Ph.D., Associate Professor at Southern Connecticut State University did. While the study is older, the information is still accurate. Families affected by hypohidrotic ectodermal dysplasia (HED) may find it helpful.
Kelly’s dissertation was titled, Perceptual and Acoustic Voice Characteristics of Children with Anhidrotic Ectodermal Dysplasia. Anhidrotic ectodermal dysplasia is more commonly called HED. You can read the entire study which was completed in 2002. Here is a summary of what we learned.
Research on Voice Quality
Limited research has been published that talks about the voice quality or characteristics of children with HED. One study published in the early 1980s addressed these voice characteristics. These researchers used spectrographic analysis (looking at the sound waves) to examine the voices of seven patients affected by ectodermal dysplasias identified as “breathy” and they attempted to find the cause of this voice difference. There appeared to be no bodily structural reason to explain the hoarse, harsh, rough quality. They proposed that reduced vocal cord lubrication (lack of moisture to prevent friction) is responsible for these differences.
Several other researchers have reported voice differences for speakers affected by ectodermal dysplasia. It has been described that the voice differences are part of the clinical manifestations of ectodermal dysplasia; meaning that these differences are just part of ectodermal dysplasias.
Cause of Raspy Voice
Over the past 60 years, most accounts of voice differences in the ectodermal dysplasias population have identified a lack of mucous in the vocal tract as being responsible for the characteristic voice. However, all of these references were based on personal accounts with no evidence to support the notion. These findings sparked the interest of Kelly Mabry as she was working on her doctorate degree in speech pathology.
Through Kelly’s affiliation with the Connecticut Children’s Medical Center Craniofacial Team she met a few families whose children with ectodermal dysplasia presented with atypical voices. She began her study “Perceptual and Acoustic Voice Characteristics of Children with Anhidrotic Ectodermal Dysplasia.”
With NFED’s help, Ms. Mabry met families and with parental permission tape-recorded children’s voices. The study focused on children ages three years to 10 years who were affected by HED.
She obtained the voice samples of 13 children affected by ectodermal dysplasia and 13 unaffected peers and presented them to a qualified group of listeners. The voices were rated for quality (normal, breathy, hoarse, rough) and severity on a 7-point scale (1=very mild to 7=very severe).
Listeners rated 92% of the speakers affected by ectodermal dysplasia as not “normal” with the majority of responses labeling the voices as “breathy” (36%) followed by “hoarse” (32%) and “rough” (24%). These findings led to the conclusion that children with HED do have atypical voice characteristics.
Ms. Mabry then analyzed the voice samples for sound and tone characteristics. A significant amount of samples showed markers for a loss of, or inefficient use of air flooding through the vocal folds. No markers for structural differences of the vocal folds were found.