Characteristics of Lithic Sound to Assess a Rock’s Predictability of Flaking

ABSTRACT

It has been suggested that a lithic resource’s candidacy for predictability of fracture when knapped, and whether or not a stone has been heat treated, can be assessed by the duration, pitch, and loudness of sound made when a stone is struck. A hammer stone machine held and struck specimens of 16 lithic types. Acoustic information was processed with a Kay Computer Speech Laboratory. Differences exist in sound duration, pitch and loudness between lithic types, un-heat-treated and heat-treated stone, and stone of the same type but of high and of low quality. Heat treated samples conduct sound waves of longer duration than unheated samples, and heat-treated samples’ sounds were louder than un-heat-treated samples. An ancient knapper could use perceptible differences in sound produced by a nodule when tapped with a hammerstone to select or discard nodules or flakes of one lithic type over another based on anticipated predictability of flaking.

KEYWORDS:

• Heat treatment and sound
• lithic material type and sound
• predictability of flaking
• sound variability
• sound when struck

Acknowledgements

For assistance and advice, we thank Randy Beach, David Crawford, Dr. Raymond L. Ethington, Dr. Frank Feng, Dr. Randall J. Miles, Dr. Barry Slansky, and Dr. W. Raymond Wood (all with University of Missouri-Columbia). Thanks to Metin Eren (Kent State University) for inspiration, and Heather N. Smith (Kent State University) and two anonymous reviewers for comments.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability

Data are available upon request to the authors.

Additional information

Notes on contributors

David S. DeForest

David S. DeForest, MA, has research interests in experimental archaeology and North American open-pit quarries.

R. Lee Lyman

R. Lee Lyman, PhD, is Professor Emeritus of Anthropology, University of Missouri, Columbia, Missouri, USA.