The Origins of Music: Preface - Preface

A less controversial technique was introduced by Laitman,Heimbuch,

and Crelin (1979) who used a direct measurement technique for describ-

ing the skull base and estimating the shape of the supralaryngeal vocal

tract.As posited by Laitman and colleagues in a series of papers and

abstracts (1982,1988,1991,1992),the primitive condition in living non-

human mammals (including nonhuman primates) is represented by a

flat,unflexed external cranial base.Based on the anatomy of the suprala-

ryngeal region,this flattening is associated with a high-positioned larynx

in living nonhuman taxa,which is correlated with a reduced capacity to

produce the varied sounds of human speech (Laitman and Heimbuch

1982;Laitman,Heimbuch,and Crelin 1979).On the other hand,con-

temporary humans have arched (flexed) skull bases (figure 14.2) that in

the living are correlated with a larynx positioned low in the throat.This

arched morphology results in the modern adult condition of a large

supralaryngeal resonating chamber capable of producing the full range

of linguistic sounds (Lieberman 1975).Thus,although not directly mea-

suring the supralaryngeal vocal tract,this technique estimates its likely

shape and infers that the angulation of the external cranial base predicts

larynx positions and speech sound capacity.Note,however,that at least

one study (Gibson and Jessee 1994) failed to find a consistent associa-

tion between features of the external cranial base and laryngeal position

in a collection of modern Americans from Texas.These observations

were tentatively confirmed by Lieberman et al.(1998) who,in a short

222 David W.Frayer and Chris Nicolay

Figure 14.2

Views of a modern human skull shows the external cranial base,three points used in deter-

mining the angle of flexion,and the highly flexed external cranial base typical of linguisti-

cally competent humans.

Fig.14.2