The process of producing, perceiving and understanding human speech
article and illustration © Robert A. Crimmins, Felton, Delaware, USA
Evolution can be a highly imperfect process but the development of human speech is not an example of that fact. The generation of speech sounds is accomplished by physiological devices that are primarily for very different purposes. Language developed long after the mechanisms that produce speech sounds were formed. The vocal cords were (and still are) primarily for closing the glottis to stop air flow out of the lungs. This is so we can hold our breath during periods of exertion when the rib cage must be rigid. The degree to which we have evolved to manipulate that device is amazing. The next time you hear an opera singer or four part harmony remember that those beautiful tones are being produced by ligaments and muscle whose primary function is as a simple closure.
We take our speech for granted because it is done so naturally but our thoughtless treatment of such a wonderful skill only adds to it’s grace. Like the athlete, the machine operator, the swordsman, typist, tradesman, and pilot we are each equipped with a tool that we adroitly manipulate without difficulty. It is another example of man’s ability to take what’s available and put it to good use. Considering the secondary nature of the tooling and what is done with it I would say it is the finest example.