The Journal of the Acoustical Society of American

Peruvian Whistling Bottles


Copyright ©1977  The Acoustical Society of America

by Steven Garrett and Daniel K. Stat (a)

Department of Physics, UCLA,
Los Angeles, California 90024
Museum of Cultural History, UCLA,
Los Angeles, California 90024

Measurements were made of the frequency and sound pressure level from 73 ceramic whistling bottles blown by compressed air.  The bottles represent nine pre-Columbian civilizations which inhabited the north and central coasts and highlands of Peru during a 2000-year time span from 500 B.C. to A.D. 1550.  We have found that Peruvian whistling bottles group acoustically by culture.  The bottles are generally regarded by anthropologists as utilitarian liquid containers with the whistle providing an amusing method of venting.  We are suggesting an alternative interpretation of the bottles as having been specifically produced as whistles.  We base this interpretation on the clustering of frequencies by individual cultures, the fact that the frequencies fall in the region of the ear's greatest sensitivity,  and the high sound pressure levels produced by the bottles when blown orally.

Introduction

Ceramic whistling bottles were produced on the north and central coasts and highlands of Peru for two thousand years beginning ca. 500 B.C. and continuing until shortly after the Spanish conquest of Peru in 1532.  Anthropologists generally regard the bottles as utilitarian containers with the whistle providing an amusing vent to facilitate the passage of air when pouring and filling with liquid.1-5  It has also been suggested that these bottles were used as whistles,  possibly in a ritual context.3, 6-8  The specimens tested in this study were found at gravesites by huaqueros  (graverobbers)  and there is nothing in the Spanish Chronicles of the New World or in the pre-Columbian Peruvian iconography that suggest their original use.

We have collected data on the harmonic structure of the sounds from 73 whistling bottles.  The 73 bottles represent nine cultures from the north and central coasts and highlands of Peru,  encompassing a time span from ca. 500 B.C. to A.D. 1550.

I.  Sample

One of us  (D.K.S.)  assembled 73 whistling bottles from private collections,  the Los Angeles County Museum of Natural History,  and UCLA's Museum of Cultural History.  All but three bottles were identified on the basis of physical appearance by Christopher B. Donnan,  Director of UCLA's Museum of Cultural History,  as belonging to one of the nine cultures listed in Table I.   (Table I and Figures 1 - 3,  6 - 7 will eventually be included).   Three bottles could not be assigned to a specific culture without ambiguity and four bottles had been restored.  The integrity of the orginial acoutical signatures of the four restored bottles could not be assured and these were not included in the sample.  Of the 69 bottles included in the sample,  53 were double chambered (Figs. 1 and 2),  14 were single chambered (Fig.3),  one was four chambered,  and one was six chambered (Fig.3).  The four bottles not included in the sample because of restoration were all double chambered.

II.  Description

All of the whistling bottles tested were made of ceramic.  The physical dimensions are 15-30 cm high,  20-30 cm long,  and 10-20 cm wide.  The bottles are comprised of one or more chamber(s) connected by an upper bridge handle,  often containing the whistle,  and a lower pottery tube that enables liquid or air to flow from one chamber to the other  (Fig. 4 and Fig. 5).  The lower tube is the sole connection between the chambers through which liquid or air can flow.  The single chambered bottles are surmounted by a tubular spout connected to an effigy by a bridge handle (Fig.3).  When the bridge handle contains the actual whistle (hereafter referred to as the "exposed-type"),  the whistle is "sounded" by means of an air stream which exits the effigy chamber through a small aperture in that chamber (Fig. 4).  In the case of the "enclosed-type" whistle,  the whistle cavity is contained within the effigy itself  (Fig. 5).

The dimensions of the whistle cavities of seven Chimú bottles were measured by filling the cavities with water from a syringe to determine their volume.  The effective diameter and length of their orifices were measured with a steel rule.  Since the whistles were in some cases partially obscured by other features of the bottles and their orifices did not always have circular cross sections,  uncertainties in measuring the diameters and/or lengths were occasionally as high as 30%.  The Helmholtz frequencies fhof the seven bottles were calculated from the following expression,  with an effective lengthl' with a correction which is a compromise between that for a flanged and unflanged tube.

fh= (c/2 pi)(S/l' V)1/2,


where S = 1/4 pi d2d is the average diameter of the orifice,  V is the volume of whistle cavity,  l' = l + 0.7d,  and c is the speed of sound in air.  Cavity volumes were typically 0.6 to 1.0 cm3;  orifice diameters were 3.5 - 4.5 mm,  and orifice lengths,  determinded by the thickness of the ceramic,  ranged from 1 - 3 mm.  Averaged over the seven bottles,  the deviation of the calculated frequencies from the measured frequencies was less than 7%.  This is excellent agreement in consideration of the uncertainties in measuring the small physical dimensions of the whistle cavities.

With respect to the multiple chambered bottles,  the traditional explanation for the whistle's function is that it acts as an air vent to permit the flow of liquid from one chamber to the other.  In the case of the single chambered bottles,  the function of the whistle is again that of an amusing way to vent the vessel.  When a bottle containing liquid is returned to an upright position after a portion of its liquid is poured from the tubular spout,  the remaining liquid,  seeking its own level,  displaces the air in the effigy chamber.  This produces an air stream which is directed across the whistle's orifice.

The current interpretation is that whistling bottles were "sounded" in this manner by means of a displacement of air by liquid.  However,  when a bottle is "sounded" in this way,  the tone produced is barely audible,  not at all the intense sound created when a bottle is blown orally through the tubular spout.  When a whistle is "sounded" orally the chamber(s) act as a surge tank to reduce wavering in the tone which may occur because of slight short-term variations in pressure at the spout.

III.  Methods

The bottles were placed in an anechoic chamber and pressurized air was used to produce the tones (Fig. 6).  A Brüel & Kjær 2203 sound-level meter was suspended inside the chamber approximately 10 cm from the whistle in a position close to where a person's ear would be if the vessel had been blown orally.  The air flow was then adjusted to give the maximum wide-band sound pressure level as indicated on the sound-level meter.  We chose the maximum sound pressure level as the place to measure the frequency of the bottles for two reasons.  The first being that it was always a unique point for each bottle.  The volume flow rate of air or the blowing pressure varied from bottle to bottle and depended on physical properties of each bottle that were irrelevant to the actual whistle.  The excess static pressure at the spout necessary to achieve the maximum sound varied from 1 - 3 kilopascals above ambient pressure,  10 - 3- cm of water as measured by a water filled U-tube.  The necessary pressure was the same whether the bottle was blown orally or by compressed air.  The second reason was that the blowing pressure necessary to achieve maximum sound pressure level was always low enough so that a person could sustain this maximum level for 15 - 20 sec.  The maximum sound pressure level for each bottle was recorded and the average sound pressure level for all bottles from a single culture is reported in Table I under L.  "Delta" L is the standard deviation of the sound pressure levels for each culture.

The output of the sound level meter was connected to a Hewlett-Packard model 3580-A Spectrum Analyzer with its bandwidth set at 10 Hz.  The frequencies and relative sound pressure levels of the fundamental and partials for each bottle was recorded.  The sound pressure level of the fundamental for each bottle is plotted against its frequency in Fig. 7.  The average frequency of the fundamental for all bottles in a single culture is listed under f in Table I and the standard deviation of the fundamentals from that culture is listed under "delta" f.  In the case of double-noted whistles,  the frequency of the partial with the highest sound pressure level was chosen for calculating the averages in Table I and plotting the frequencies of the bottles in Fig. 7.

The partials were harmonics of the fundamental and typically decreased monotonically with increasing frequency.  The fundamental was typically 60 dB above the noise level which was produced by the sound of the air rushing out of the bottle.  In some cases as many as seven partials were distinguishable.

IV.  Discussion and Conclusion

An examination of the frequency data in Table I and Fig. 7 strongly suggests that the nine cultures represented produced whistles in a frequency range specific to the particular culture which produced the bottles.  The standard deviation for any one culture is significantly less than the standard deviation for the entire sample.  The average frequency is not the sole distinguishing cultural characteristic of the bottles.  In 20 of the 69 bottles in the sample,  the whistle was contained within the effigy chamber.  All 14 bottles from the Gallinazo,  Vicus,  Moche,  and Huari cultures spanning a time period from 400 B. C. to A. D. 700 were of this "enclosed-type."  In addition two of the four bottles not included in the sample because of restoration were "enclosed-type" whistles and both of these were from the Vicus culture as well.  Of the remaining six "enclosed-type" whistles two were unspecified culturally,  three were Chimú, and one was an Inca whistle.

Fourteen whistles produced two distinct tones depending on the blowing pressure applied at the spout.  A lower frequency tone,  with a frequency 0.65±0.1 times the higher frequency tone,  is produced when the blowing pressure is reduced by 1/3 to 1/2 of the pressure necessary to produce the tone of maximum sound pressure level.  The wide-band sound pressure level of the lower frequency tone is typically 4 - 16 dB less than the tone of maximum sound pressure level for these double-noted whistles.

Thirteen of the 14 double-noted whistles were of the "enclosed-type,"  and one was of the "exposed-type."  The single "exposed-type" double-noted whistle was from the Inca culture.  Nine of the 14 double-noted whistles belonged to the Gallinazo,  Vicus,  Moche,  or Huari cultures.  Additionally,  the two restored Vicus whistles not included in the sample were also double-noted "enclosed-type" whistles.  Of the remaining five double-noted whistles,  one was Chimú,  two were Inca,  and two were unspecified culturally.

Only one of 50 examples where the whistle was of the "exposed-type" produced a double note and this was the Inca example mentioned above.  All three examples from the Recuay culture,  spanning a time period of A. D. 100 through A. D. 500 were single-noted "exposed-type" whistles.  All but three of 48 examples of Chancay,  Chimú,  and Inca cultures spanning a time period of A. D. 700 through A. D. 1550,  produced a single tone irrespective of the air pressure,  and all but four of the 48 were of the "exposed-type."  The four which were of the "enclosed-type" were three Chimú,  and one Inca.  One of the "enclosed" Chimú and the Inca "enclosed" were double-noted.  Two "enclosed" Chimú were single-noted, and one "exposed-type" Inca was double-noted as mentioned above.

The average frequency of the Gallinazo,  Vicus,  Moche,  and Huari whistling bottles is 1320 Hz while the average frequency for the Recuay bottles is 2000 Hz.  The average frequency for the Chancay,  Chimú,  and Inca bottles is 2670 Hz.  It is apparent that the earlier cultures tended to produce double-noted,  low-frequency,  "enclosed-type" whistles while the later cultures generally produced single-noted,  high-frequency,  "exposed-type" whistles.  In that the frequency is determined by the whistle cavity and not the pottery style,  the frequency would be an additional method for determining cultural origins of whistling bottles.

On the basis of these data we suggest the possibility of using the frequency and type of whistle  (enclosed vs exposed)  as an additional means for determining cultural origins of Peruvian whistling bottles.

Reconsideration of Table I and Fig. 7 show that the frequencies of the bottles produced by a single culture tend on the average to be within ± 14% of the average frequency for that individual culture.  On the basis of the small fraction of an octave spanned by the frequencies of all bottles in any single culture we are reasonably certain that the bottles were not used as musical instruments.  However,  when two or more bottles from a given culture are played simultaneously the perception of a wavering low frequency tone is very distinguishable.  The clustering of frequencies by individual culture,  the position of the frequencies in the region of the ear's greatest sensitivity  (1 - 4 kHz),  and the high sound levels produced by the bottles when blown orally,  strongly suggest that the Peruvians produced whistling bottles as whistles  -  as contrasted to the traditional interpretation of them as utilitarian liquid containers.

Acknowledgments

We would like to thank Professor Isadore Rudnick for the use of his laboratory and many stimulating suggestions.  We wish to thank also,  Dr. Charles Rozaire for making available the collections of the Los Angeles County Museum of Natural History,  and Professor Christopher B. Donnan for helping to identify the sample and for making available the collections of UCLA's Museum of Cultural History.  We also gratefully acknowledge the graphics by Patrick Finnerty,  the photographs by Jas. Abbott,  and the help of Gary Olsen and Scott Adams during the collection of the acoustical data.  Finally,  we thank Dr. R. W. Young for his helpful comments during the revision of the manuscript.



Published in:
The Journal of the
Acoustical Society of America
,
Vol. 62, No. 2,
August, 1977.


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Footnotes

(a) Address:  Center for Integral Medicine,  P.O. Box 955, Pacific Palisades, CA 90272.
  [Addendum (24 Oct. 2012):   Daniel K. Statnekov,  (aka Daniel K. Stat)
  current address:   1201 N. Orange Street, Suite 700,  Wilmington, Delaware 19801.
  daniels@statnekov.com

(1) W.C. Bennett,  "Archaeology of the Central Andes,"  in Handbook of South American Indians,  edited by J.H. Steward (Cooper Square,  New York,  1963),  Vol. 2.

(2) C.W. Mead,  Old Civilizations of Inca Land  (American Museum of Natural History,  Handbook Series No. 11,  New York, 1935).

(3) S. Martí,  Instrumentos Musicales Precortesianos (Instituto Nacional de Anthropología e Historia, México, 1968), 2nd ed., Chap. 6.

(4) M.E. Rivero and J. J. von Tschudi,  Translated by F. L. Hawkes,  Peruvian Antiquities (A. S. Barnes,  New York,  1854;  Krause Reprint Co.,  New York,  1971).

(5) A. H. Verrill, Old Civilization of the New World (Tudor,  New York,  1938).

(6) P. T. Furst,  "Whistling Pots from Mexico and Peru,"  Quarterly Los Angeles County Museum 3,  No. 2,  10-14 (1964).

(7) K. G. Izikowitz,  Musical and Other Sound Instruments of the South American Indians (Elanders Boktryckeri Aktiebolag Goteborg,  Sweden, 1934;  republished by S. R. Publishers Ltd.,  1970).

(8) D. K. Stat,  "Double Chambered Whistling Bottles:  A Unique Peruvian Pottery Form,"  J. Transpersonal Psychology,  2,  157 - 162 (1974).

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