Our voice, like our handwriting, is an individual signature.

Just answering Hello on the phone is enough for our relatives or closed friends to identify who is speaking.

The daughter or the son of a friend, who speaks just like their parents, sometimes mistakes us. Study on monozygotic twins showed that the voice pitch can be a familial characteristic, which can be useful in the identification of twins.

 Also our voices may express our emotions, such as anger, stress, and happiness like our facial muscles do, mainly through the pitch of our voice. There are studies in the world of forensic science on vocal stress analysis. But none of them have found so far a reliable way of detecting lie based on recording laryngeal micro-tremor.

 Also our accent told people where we come from geographically and socially.

 So, presenting with a voice disorder can be emotionally difficult as not only the oral communication become laborious, but also the way of expressing our emotions is impaired, and part of our identity is lost.

 –Spasmodic dysphonia, is a dystonic spasm of the vocal cords when speaking and there are 2 main types of spasmodic dysphonia.

1-In the adductor type, the most common form the voice is strained, strangled, frequently interrupted by voiceless pauses, because the vocal cords have difficulties to spread apart when speaking, In that case, the dystonic muscles are the thyro-arythenoids muscles or adductor muscles, which are responsible of getting the vocal cords closed to each other’s.

2-In the abductor type, the less common form, the voice is breathy, with prolonged voiceless consonants because of difficulties with voice onset following voiceless sounds such as /h/, /s/, /f/, /p/, /t/, and /k/. The muscles, which are responsible of spreading apart the vocal cords, are the Crico-pharyngeal muscles or abductor muscles.

 

-Emotional factors can influence spasmodic dysphonia

Stress can precede the onset, or worsen the symptoms, but surprisingly patients report that screaming, crying, laughing, and singing can be normal. This variability of the symptoms can be disconcerting for the patient and raise suspicion of psychogenic pathology (due to psychological problems) in the entourage of the patients and even the doctors. The capricious nature of the dystonic symptoms has to be explained for a better acceptation of the condition .

–Botulinum toxin injections into the vocal cords are the most efficient treatment of this condition, which curiously not only restore the voice fluidity in case of adduction dysphonia but also the voice personality with pitch and accent. Repeated injections every 3 to 6 months are required to maintain a good voice.

-References:

Voice similarity in identical twins. Van Gysel WD, Vercammen J, Debruyne F. Acta Otorhinolaryngol Belg. 2001;55(1):49-55.

 Voice Onset Time Production in Older and Younger Female Monozygotic Twins
Jack Ryalls, Heather Shaw, Marni Simon. 
Folia Phoniatr Logop 2004;56:165-169.

 Voice stress evaluators and lie detection. Hollien H, Geison L, Hicks JW Jr. J Forensic Sci. 1987 Mar;32(2):405-18.

 Voice – How humans communicate? Manjul Tiwari and Maneesha Tiwari , J Nat Sci Biol Med June 2012

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3361774/

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 Patient perceptions of factors leading to spasmodic dysphonia: a combined clinical experience of 350 patients. Childs L, Rickert S, Murry T, Blitzer A, Sulica L. Laryngoscope. 2011 Oct;121(10):2195-8.