Today marks the observation of World Voice Day all over the world. This day has been set aside to contemplate and celebrate the wonders of the human voice.

There are so many things I could write about on this special day, so I wanted to share with you just several amazing facts about the human voice:

1. While listening to forty seconds of surgeon-patient consultations from which words had been filtered out, just leaving the tone of voice alone, listeners were able to tell which doctors had been sued for malpractice and which hadn’t. (Nalini Ambady et al, ‘Surgeons’ Tone of Voice: a Clue to Malpractice History’, Surgery, 2002: 132.)
2. The voice can function as a breathalyzer, a rough guide to intoxication. (Grazyna Niedzielska et al, ‘Acoustic Evaluation of Voice in Individuals with Alcohol Addiction’ (Folia Phoniatrica et Logopaedica 46: 115– 122, 1994).
3. No vocal learning by imitation takes place in mammals below humans; apart from some birds, only humans have voluntary control over the acoustic nature of their vocal utterances, can learn vocal patterns by imitation, and even invent new ones.(Uwe Jurgens, ‘On the Neurobiology of Vocal Communication’, in Hanus Papousek et al, eds., Nonverbal Vocal Communication: Comparative and Developmental Approaches (Cambridge: Cambridge University Press, 1992). See chapter 11 for an elaboration.)
4. Women’s vocal folds (sometimes called vocal cords) perform more than one million oscillatory cycles a day. Men’s accomplish around half a million in the course of a day. (Jan G. Svec et al, ‘Vocal Dosimetry: Theoretical and Practical Issues’, in G. Schade et al, eds., Proceeding Papers for the Conference, Advances in Qualitative Laryngology, Voice and Speech Research (Stuttgart: IRB Verlag, 2003). This research therefore makes an interesting contribution to the heated topic of whether men or women talk more!)
5. The invention of the laryngoscope has been attributed historically (and perhaps apocryphally) to Manuel Garcia II, the famous voice teacher of the nineteenth century. (Manuel Patricio Rodriguez Garcia, ‘Transactions of the Section of Laryngology, International Congress of Medicine’, London, 1881 in British Medical Journal, 17 February 2001.
6. If the voice emerged straight out of the larynx, it would make a poor, thin sound. (Margaret C.L. Greene, Disorders of the Voice (Austin, Texas, PRO-ED, 1986).
7. The average larynx can stretch to over two octaves in range, sometimes even three. At the same time few of us employ more than one octave when we speak, mostly staying in the lower part of our total voice range. (D.B. Fry, The Physics of Speech. Cambridge: Cambridge University Press, 1979).
8. Ear and voice complement each other: both are activated by the movement of air. Just as air makes the larynx vibrate, so it’s the air in the form of sound waves that causes the eardrum to vibrate – the basis of hearing. To listen to someone’s voice is therefore ‘a partnership of vibration’. (Alfred A. Tomatis, The Conscious Ear. New York: Station Hill Press, 1991).
9. How loud is a loud voice? The average conversational voice, with speaker and listener some three feet apart, is 60 dB. Quiet speech hovers around 35-40 dB, while shouting rises to 75 dB. Rustling leaves measure 10 dB, and loud radio music 80 dB. Around 120 decibels creates a sensation akin to touch, and above this we hit the pain threshold. (Donna Jo Napoli Linguistics, New York: Oxford University Press, 1996).
10. When archaeologists excavated a Neanderthal burial site in the Kebara Cave on Mount Carmel in Israel in 1987, they found a human skeleton some 60,000 years old that possessed a complete and well-preserved hyoid bone, the first ever discovered in a fossil hominid. This small, U-shaped bone, located between the lower jaw and the spinal column, is supposedly a good indicator of the anatomical position of the vocal tract, because the tract and larynx always sit beneath it. On the evidence of this bone, the Neanderthals had a low-lying larynx and so were anatomically capable of speaking. (Baruch Arensburg and Anne-Marie Tillier, ‘Speech and the Neanderthals’, Endeavour, vol. 15, no. 1, 1991.)