Breath Pressure in Ethnic Wind Instruments

This original research study is available in two open-access formats: as a research article available in PDF format ([Goss 2013] ), and this web page, which provides a version of the same information that is a bit more colloquial, has links into the rest of Flutopedia, and has some additional material at the end. This web page, as well as the corresponding research article in PDF, are licensed under the Creative Commons Attribution-Noncommercial 3.0 license.

Please cite this page as: Goss, C. (2013). “Breath pressure in ethnic wind instruments”. Flutopedia: http://www.Flutopedia.com/breath_pressure.htm, August 21, 2013. Retrieved [DATE-of-Retrieval].

If you have feedback on this research study, please contact me at clint@goss.com.

Summary

High intraoral pressure generated when playing some wind instruments has been linked to a variety of health issues. Prior research has focused on Western classical instruments, but no work has been published on ethnic wind instruments. This study measured intraoral pressure when playing six classes of ethnic wind instruments (N = 149): Native American flutes (n = 71) and smaller samples of ethnic duct flutes, reed instruments, reedpipes, overtone whistles, and overtone flutes. Results are presented in the context of a survey of prior studies, providing a composite view of the intraoral pressure requirements of a broad range of wind instruments. Mean intraoral pressure was 8.37 mBar across all ethic wind instruments and 5.21 ± 2.16 mBar for Native American flutes. The range of pressure in Native American flutes closely matches pressure reported in other studies for normal speech, and the maximum intraoral pressure, 20.55 mBar, is below the highest subglottal pressure reported in other studies during singing. Results show that ethnic wind instruments, with the exception of ethnic reed instruments, have generally lower intraoral pressure requirements than Western classical wind instruments. This implies a lower risk of the health issues related to high intraoral pressure.

Figure 1. Summary of intraoral pressure ranges in wind instruments. The horizontal axis plots the minimum and maximum intraoral pressure for each instrument or instrument class. Measurements from this study are combined with results reported in the literature cited in Tables 1 and 2 contained in the Appendix.

Introduction

Breath pressure (also called “back-pressure” or “intraoral pressure”) is an important physiological metric related to playing wind instruments. The range of intraoral pressure generated when playing an instrument is dependent on the instrument. Within that range, players alter their breath pressure to control the volume, pitch, and tone produced by the instrument.

In ethnic wind instruments, the breath pressure requirements are determined by many factors related to the design parameters of the instrument (see [Prairie 2011]  and, for a more general treatment, [Prairie 2006] ).

Intraoral pressure is a consideration when choosing a wind instrument to play. Wind instruments with high intraoral pressure requirements have been linked to a number of health issues, in particular:

• Velopharyngeal incompetency (VPI), a condition where the soft palate or pharyngeal walls fail to separate the nasal cavity from the oral cavity ([Weber-J 1970], [Dibbell 1979], [Dalston 1988], [Ingrams 2000], [Schwab 2004], [Stasney 2003], [Malick 2007], [Kreuter 2008], [Evans-A 2009], [Evans-A 2010], [Evans-A 2011]).
• Pneumoparotid, where the parotid salivary gland behind the ear becomes enlarged due to air insufflation ([Kirsch 1999], [Kreuter 2008], [Lee-GG 2012]).
• Hemoptysis ([Kreuter 2008]).
• Increased intraocular pressure and intermittent high-pressure glaucoma ([Schuman 2000], [Schmidtmann 2011]).
• Hypertension (possibly — see [Dimsdale 1995] and [Larger 1996]).
• Barotrauma causing reduced pulmonary function ([Deniz 2006]).
• Laryngocele, a congenital lung condition seen in glassblowers due to high breath pressures ([Kreuter 2008]). [Lee-GG 2012] reports pressures as high as 200 mBar for glassblowing.

Given the range and severity of these potential health issues, preference for wind instruments with lower intraoral pressure requirements is prudent.

Intraoral pressure has been studied in speech, singing, and playing various wind instruments of the Western classical tradition. However, no studies measuring intraoral pressure in ethnic wind instruments have been reported in the literature.

Method

Musical Instruments

Six classes of musical instruments were studied (in some cases, instruments are identified with the culture that initiated the design of the instrument, or the predominant culture where the instrument is presently found. These are provided solely for the purpose of identifying the instrument):

Native American flutes (n = 71). A front-held flute that has an external block and an internal wall that separates an air chamber from a resonating chamber that contains open finger holes. Hornbostel–Sachs (HS) class 421.211.12 and 421.221.12 — edge-blown aerophones, with breath directed through an external or internal duct against an edge, with finger holes. Native American flutes used in this study were crafted by 32 different flute makers. These flutes play primarily in the first register, with some flutes having a few notes in the second register. Range is typically limited to 12–15 semitones.

Ethnic duct flutes (n = 46). HS class 421.221.12 — edge-blown aerophones, with breath directed through an external or internal duct against an edge, with finger holes. Typical play on these instruments is done in the first register, with normal play extending to several notes in the second register and possibly one note in the third register (sounding a major twelfth). Ethnic duct flutes in this study include the Irish whistle, Slovakian pistalka (píšťalka), Ukrainian and Russian sopilkas (Cопiлка, Сопел), Romanian frula, Indonesian suling, Georgian salamuri (სალამური), Bolivian tarka, Mesoamerican clay flutes, flutes characteristic of the Tarahumara culture, and Russian sivril.

Ethnic reed instruments (n = 4). HS class 422.1 and 422.2 — reed aerophones, with breath directed against one or two lamellae (reeds) which vibrate and set the air in a resonating chamber in motion. They are limited to play in one register and typically have a limited range of no more than 14 semitones. Ethnic reed instruments measured in this study comprise a Russian jaleika, an Armenian duduk (Դուդուկ), a Kenyan bungo'o, and a bamboo saxophone.

Ethnic reedpipes (n = 12). HS class 422.31 and 422.32 — reed aerophones, single or double reedpipe with a free reed that vibrates through/at a closely fitted frame, with finger holes. They are limited to play in one register and typically have a limited range of no more than 14 semitones. Note that pitch on these instruments often responds inversely to ethnic duct flutes — decreasing as breath pressure is increased. Ethnic reedpipes measured in study comprise the Chinese bawu (巴烏), Chinese hulusi (葫蘆絲), and Laotian kaen or khene (ແຄນ).

Ethnic overtone whistles (n = 8). HS class 421.221.12 — edge-blown aerophones, with breath directed through an internal duct against an edge, without finger holes. Due to the lack of finger holes, they have a fixed-length resonating chamber. They are designed to play high into the overtone series — sometimes as high as the tenth register. To accomplish this, they tend to have relatively long resonating chambers compared with their diameter. Ethnic overtone whistles measured in this study include the Slovakian koncovka, Norwegian willow flute (seljefløyteta), and an overtone flute of the North American Choctaw culture.

Ethnic overtone flutes (n = 8). HS class 421.221.12. HS class 421.221.12. These flutes share some of the characteristics of ethnic duct flutes and ethnic overtone flutes: they have a limited number of finger holes (typically three or four) and are designed to play high into the overtone series. Ethnic overtone flutes measured in this study include the Slovakian fujara, tabor pipe, and flutes of the North American Papago and Pima cultures.

Measurement

Breath pressure was measured using a system constructed of components supplied by Omega Engineering (Stamford, CT). The setup consisted of:

• Meter: One DP25B-S strain meter, shown on the right.
• Sensor: One PX26-001DV piezoresistive pressure sensor. This sensor is designed for wet conditions and provides a differential voltage proportional to the pressure applied, in the range of 0–1 PSI.
• One CX136-4 wiring harness.
• Tubing: Clear plastic flexible tubing, ⁵⁄₁₆″ outside diameter, ³⁄₁₆″ inside diameter (55″ for measurements, 128″ for water-column calibration).

The meter was configured with settings provided by Omega engineering to provide readings in the range 0.001 – 1.000 PSI in thousandths of a PSI. Based on the combined specifications of the sensor and the meter, the factory calibration of the system should be within ±2.20%. This was confirmed by calibrating the unit against the differential height of columns of water in an extended section of tubing, at four pressure points. The greatest deviation was +2.05%.

All readings were converted to milliBars (mBar), including readings from cited sources that are given in a wide variety of units, including cm H₂O, in H₂O, mm HG, kPa, and psi.

Procedures

All measurements were taken at 72 °F on instruments that were fully acclimated to that ambient room temperature. Movable parts of an instrument were adjusted to their typical or recommended playing position. Each instrument was warmed up using two long breaths into the finger holes.

The open end of the tubing, cut square, was placed in the mouth perpendicular to the general airflow while the musical instrument was played.

Native American flutes. Nine measurements were attempted for each flute, three measurements on each of three notes:

• The root note, typically fingered .
• The fifth note, seven semitones above the root note, typically fingered or . For flutes tuned to the diatonic major scale, the fingering was typically used.
• The octave note, typically fingered or . For flutes tuned to the diatonic major scale, the fingering was typically used.

These three notes were played at three dynamics (volumes) by varying breath pressure: forte (f), mezzo-forte (mf), and piano (p). Rather than attempting to produce these dynamics subjectively, a Korg OT-120 pitch meter was used, set to A=440 Hz, equal temperament. A reference pitch (RP) for each note was established based on an “on-pitch” indication on the pitch meter. In the case of instruments that were not tuned to concert pitch, the RP was established using a breath pressure that subjectively produced a good tone.

Pressure readings for mf were taken after establishing a steady tone, with no vibrato, that produced the RP. Readings for f and p were taken with breath pressure that produced readings of 30 cents above and below the RP, respectively. The readings do not show effects of any articulation at the start of the note.

In some cases, it was not possible to produce all nine combinations of pitches and dynamics. For example, increasing breath pressure above mf on the root note on some flutes causes the flute to jump into the next register. On some diatonic flutes, readings were not possible when attempting to play p on the octave note, since the flute could not maintain resonance in the second register at lower breath pressure.

Ethnic duct flutes. Measurements were taken as with Native American flutes. Most of these flutes use the fingering to produce the octave not in the second register. In addition, the fundamental note in each of the higher registers was attempted, as high as was possible on the instrument. Pressure measurements in these higher overtone registers were taken by establishing the pitch and then reducing breath pressure slightly to a point where the tone was stable — reference to precise tuning was not used in these higher overtone registers.

Ethnic reed instruments. Measurements were taken as with Native American flutes, except that measurements were taken only for the mf dynamic.

Ethnic reedpipes. Measurements were taken as with Native American flutes, but it was only possible to use breath pressure to bend pitch ±30 cents on one instrument. Therefore, most measurements were taken at the mf dynamic.

Ethnic overtone whistles. One pressure measurement was taken for each note in each register by establishing the pitch and then reducing breath pressure slightly to a point where the tone was stable — reference to precise tuning was not used for this class of instruments.

Ethnic overtone flutes. Measurements were taken as with ethnic duct flutes, except that the measurement for the fifth note was taken using the fingering or in the first register, regardless of what pitch was produced.

Literature Survey

Results

The composite pressure (CP) for a given instrument is the mean of all measurements for that instrument, including measurements at the various pitches and dynamics that were attainable. The mean intraoral pressure for a group of instruments is the mean of the CP values for the instruments in that group. (This approach to the analysis was taken – rather than simply averaging all measurements from the group of instruments – since: (a) different instruments contributed different numbers of measurements (because of the limitations of some instruments as noted in the Procedures section) and (b) because the coefficients of variation of measurements for a given flute were reasonably low – averaging 54.3%.)

The mean intraoral pressure of all ethnic wind instruments in this study was 8.37. Because the CP values across the range of instruments in this study do not show an normal distribution, no standard deviation is reported. (The standard deviation of the CP values for all instruments calculated by traditional methods is ±8.58 mBar.)

Figure 1 provides an overview of the minimum and maximum intraoral pressure for each instrument or class of instruments, including measurements from this study and a survey of available literature. See Tables 1 and 2 in the Appendix for the source of all data points from prior studies.

Subsequent figures plot pitch on the horizontal axis, grouped into half-octave ranges. For example: C3–F3, F#3–B3, … , C6–F6, and F#6–B6 with data points plotted at D and G# within each range. The exception is a single measurement at the bottom of the set of half-octave ranges. In that case, the data point is plotted at the actual concert pitch for that measurement.

Intraoral pressure measured on Native American flutes ranged from a minimum of 0.83 mBar to a maximum of 20.55 mBar. The mean intraoral pressure across all Native American flutes was 5.21 ± 2.16 mBar. Because of limitations on some flutes noted previously, of the 639 possible combinations of pitches and dynamics on 71 flutes, 605 actual measurements were taken.

Figure 2 charts the mean intraoral pressure at the f dynamic (+30 cents) and the p dynamic (–30 cents), as well as the maximum and minimum of measurements at those dynamics, respectively. See Table 3 in the Appendix for all data values plotted on Figure 2.

Figure 2. Native American flute – intraoral pressure. Pitches are grouped into half-octave ranges, except for the single low measurement taken at E3. f = forte, measured at reference pitch (RP) + 30 cents. p = piano, measured at RP – 30 cents. RP is concert pitch based on A=440 or, for instruments not tuned to concert pitch, a breath pressure that subjectively produced a good tone.

Figure 3 places the average f and p results for Native American flutes in the context of intraoral and subglottal pressure measurements for speech that have been reported in prior studies.

The subglottal measurements reported in [Hodge-FS 2001] for male loud speech (at 75% of their maximum dynamic range) does not have associated pitch information, so Figure 3 uses the typical male pitch range from [Williams-J 2010]. Likewise, the intraoral pressure measurements for consonants from [Subtelny 1966], table 1 (as cited in [Baken 2000], table 8-5) use the suggested pitch ranges for males, females and children from [Williams-J 2010]. [Enflo 2010] provides measurements for the lower limits of phonation at which speech becomes possible. Note that only the lower two frequencies of the male and female lower phonation limits are plotted. See Tables 2 and 3 in the Appendix for all data values plotted on Figure 3.

Figure 3. Speech and Native American flutes – intraoral pressure. Pitches for Native American flutes are grouped into half-octave ranges, except for the single low measurement taken at E3. f = forte, measured at reference pitch (RP) + 30 cents. p = piano, measured at RP – 30 cents. RP is concert pitch based on A=440 or, for instruments not tuned to concert pitch, a breath pressure that subjectively produced a good tone. ff (fortissimo), pp (pianissimo), and mf / mp (mezzo-forte / mezzo-piano) are general indications of dynamics that are defined specifically in each of the cited references. The error bars for speech represent one standard deviation..

Figure 4 introduces a change in the vertical scale of pressure by a factor of five to accommodate higher pressure for musical instruments reported in the literature. Pressure measurements are plotted for the bassoon and oboe from two sources.

Figure 4. Double-reed instruments and Native American flute – intraoral pressure. Pitches for Native American flutes are grouped into half-octave ranges, except for the single low measurement taken at E3. f = forte, measured at reference pitch (RP) + 30 cents. p = piano, measured at RP – 30 cents. RP is concert pitch based on A=440 or, for instruments not tuned to concert pitch, a breath pressure that subjectively produced a good tone. ff (fortissimo), pp (pianissimo), and mf / mp (mezzo-forte / mezzo-piano) are general indications of dynamics that are defined specifically in each of the cited references. The error bars represent one standard deviation.

Figure 5 plots reported measurements on four additional Western classical instruments: the clarinet, alto saxophone, Western concert flute, and the alto recorder. See Table 1 in the Appendix for numeric data values.

Figure 5. Woodwind instruments – intraoral pressure. ff (fortissimo), pp (pianissimo), and mf / mp (mezzo-forte / mezzo-piano) are general indications of dynamics that are defined specifically in each of the cited references.

Mean intraoral pressure on ethnic duct flutes was 7.26 ± 3.93 mBar and spanned a range of 0.48–47.23 mBar. This range includes what might be considered extreme playing techniques on these instruments, since they were played as high as the ninth register in keeping with the procedures for this study. The subset of measurements on these instruments limited to playing at the reference pitch in registers 1–3, what might be considered a normal range of play on these instruments, gives a mean intraoral pressure of 5.75 ± 3.29 mBar and spanned a range of 0.48–25.86 mBar.

Figure 6 plots the results across the pitch range of ethnic duct flutes. It also plots subglottal pressure measurements from the literature for singing. See Tables 2 and 4 in the Appendix for all data values plotted on Figure 6.

Figure 6. Ethnic duct flutes and singing – intraoral and subglottal pressure. Pitches for ethnic duct flutes are grouped into half-octave ranges. f = forte, measured at reference pitch (RP) + 30 cents. p = piano, measured at RP – 30 cents. RP is concert pitch based on A=440 or, for instruments not tuned to concert pitch, a breath pressure that subjectively produced a good tone. ff (fortissimo) and pp (pianissimo) are general indications of dynamics that are defined specifically in each of the cited references.

Figure 7 plots the profile for three classes of instruments from this study:

• Ethnic reed instruments had a mean intraoral pressure of 50.38 ± 11.45 mBar and a range of 28.96–82.74 mBar.
• Ethnic reedpipes had a mean intraoral pressure of 18.07 ± 4.26 mBar and a range of 7.93–35.85 mBar.
• Ethnic overtone whistles had a mean intraoral pressure of 11.01 ± 4.84 mBar and a range of 0.28–64.26 mBar.

See Tables 5, 6, and 7 in the Appendix for all data values plotted on Figure 7.

Figure 7. Ethnic wind instruments – intraoral pressure. Pitches are grouped into half-octave ranges, with each indicator showing the maximum or minimum intraoral pressure recorded across all measurements taken in that half-octave pitch range.

Mean intraoral pressure on ethnic overtone flutes was 6.94 ± 3.14 mBar and spanned a range of 0.55–30.68 mBar. Figure 8 plots the results across the pitch range of these flutes. It also plots intraoral pressure measurements for four brass instruments from the literature. See Table 8 in the Appendix for all data values plotted on Figure 8.

Figure 8. Brass instruments and ethnic overtone flutes – intraoral pressure. Pitches for ethnic overtone flutes are grouped into half-octave ranges, with each indicator showing the maximum or minimum intraoral pressure recorded across all measurements taken in that half-octave pitch range. ff (fortissimo), pp (pianissimo), and mf / mp (mezzo-forte / mezzo-piano) are general indications of dynamics that are defined specifically in each of the cited references.

Breath Pressure Profile

In addition to the primary focus of this study, the measurements collected can shed light on some other issues of wind instrument design. One relates to the concept of a breath pressure profile (BPP) – the graph of intraoral pressure requirements on a single instrument or class of instruments as the player ascends the instruments scale.

Figure 9 charts the BPP for a subgroup of 67 Native American flutes. (The four Native American flutes that could not maintain resonance at the p dynamic were excluded from this subgroup.)  

Figure 9. Breath pressure profile across the Native American flute range (N = 67). f = forte, measured at reference pitch (RP) + 30 cents. mf / mp = mezzo-forte / mezzo-piano, measured at RP. p = piano, measured at RP – 30 cents. RP is concert pitch based on A=440 or, for instruments not tuned to concert pitch, a breath pressure that subjectively produced a good tone.

This chart shows that, on the average, Native American flutes are constructed assuming a modest increase in breath pressure as the player moves up the scale, from 3.72 mBar at the root, to 4.74 mBar on the fifth, to 5.40 mBar on the octave note. It also demonstrates that the increase in breath pressure is, on average, linear through the three notes measured and that the linear relationship holds across changes in dynamics.

Figure 9 also shows that a larger change in breath pressure is needed to raise pitch by 30 cents from concert pitch than to lower pitch by 30 cents. These results use the average readings across the three pitches at each of the dynamics: from the average  intraoral pressure of 4.62 mBar for concert pitch, raising pitch by 30 cents required 3.42 mBar more pressure (+74.0%) and lowering pitch by 30 cents required 1.70 mBar less pressure (−36.9%).

Figure 10 shows another BPP plot of the primary notes for a single, well-tuned, six-hole, Native American flute. The lines on this plot are straight and pass through the pressure measurements for the root and the octave notes. The middle line for the mf readings at RP shows a slight increase in breath pressure as the player ascends the scale. Given that the upper and lower lines represent a deviation of 30 cents, it is apparent that the variations in tuning on each of the primary notes across the range of the instrument are no more than a few cents.

Figure 10. Breath pressure profile for a single Native American flute. f = forte, measured at reference pitch (RP) + 30 cents. mf / mp = mezzo-forte / mezzo-piano, measured at RP. p = piano, measured at RP – 30 cents. RP is concert pitch based on A=440.

Discussion

Figure 2 highlights an interesting comparison between the intraoral pressure involved in speech and playing Native American flutes. This class of flutes grew from a tradition of poetic speech ([Nakai 1996], page 41), and Figure 2 lends empirical evidence to that historical link. Many aspects of speech do not involve intraoral pressure, since the mouth is often open. However, the limits of subglottal pressure and intraoral pressure involved in male loud speech, plosives and fricatives, and the lower phonation thresholds provide a striking correspondence to the limits of intraoral pressure for Native American flutes measured in this study.

A comparison between Figures 4, 5, and 7 shows that the intraoral pressure involved in playing ethnic reed instruments are roughly aligned with those of Western double-reed and single-reed instruments. Lower intraoral pressure was observed in ethnic reedpipes. It is interesting that the class of ethnic reedpipes includes instruments such as the Chinese bawu and hulusi that are generally widespread in use with amateur rather than professional musicians.

Play on ethnic duct flutes shows a rather large range on Figure 6. However, restricting play to a normal range on these instruments reduces the charted maximum intraoral pressure from 47.23 mBar to 25.86 mBar. This places ethnic duct flute roughly aligned with the one example of a Western duct flute, the alto recorder, charted in Figure 5.

The two classes of ethnic overtone instruments charted in Figures 7 and 8 show that, even though these instruments can perform in a wide range of registers and pitches, they generally have low intraoral pressure requirements. The exception for these instruments is high pressure in ethnic overtone flutes in the extreme upper registers of these instruments. Given that these upper registers are used very briefly in typical play on these instruments, the transient use of these pressure spikes may allow players to avoid the health issues associated with high intraoral pressure.

Aside from the class of ethnic reed instruments that were part of this study, it appears that ethnic wind instruments, in general, have lower intraoral pressure requirements than most Western classical wind instruments.

The development of the concept of breath pressure profile in Figures 9 and 10 demonstrate that an intraoral pressure meter could be a significant aid to tuning wind instruments. The current practice among makers of these instruments is to use their own subjective personal preferences for breath pressure when tuning the instrument across the range of pitches. The use of an intraoral pressure meter would allow the maker to choose a desired breath pressure profile and objectively tune to that specific profile.

Limitations

Because the meter used in this study required a steady-state pressure of at least 333 msec, short-term intraoral pressure changes could not be measured. This may be particularly important for instruments such as the Slovakian fujara, where short air bursts are used to very briefly sound in the extreme upper registers of the instrument

Other limitations include:

• The use of a single subject, the investigator.
• The widely varying conditions across the set of prior studies surveyed for the purpose of comparing instrument characteristics.
• The subjective evaluation of tone in establishing a reference pitch in the case of instruments that were not tuned to concert pitch.

Conclusions

This study was motivated by reports on a range of health issues associated with high intraoral pressure in some Western classical wind instruments and a lack of research in this area in ethnic wind instruments. Intraoral pressure was measured in six classes of ethnic wind instruments, and results were presented in the context of a survey of results across a broad range of wind instruments.

The results show that ethnic wind instruments, with the exception of ethnic reed instruments, have generally lower intraoral pressure requirements than Western classical wind instruments. The implication is that health issues that have been linked to high intraoral pressure in other studies are not an issue for these classes of ethnic instruments.

References

For a general bibliography in the areas covered by this article, see Breath Pressure References.

Appendix — Data Tables

This appendix provides numerical data for all charted data points that appear in the figures above.

Data from Prior Studies

Table 1. Musical Instrument Pressure Measurements Cited from the Literature

Instrument	Source	N	Concert Pitch	Dyn	IOP (mBar)	Dyn	IOP (mBar)	Figure	Notes
Alto Recorder	[Garcia 2010], Figure 5.13, graphic interpolation	1	F4	ff	2.60	ppC	1.25	5
			F5	ff	5.20	pp	2.60
			F6	ff	17.75	pp	8.00
			A6	ff	30.10	pp	9.40
Alto Saxophone	[Fuks 1996], Figures 16 and 18, graphic interpolation	2	F3	ff	27.17 ±2.80	pp	22.91 ±0.77	5
			G4	ff	57.65 ±22.91	pp	20.95 ±2.87
			A5	ff	38.94 ±4.62	pp	19.05 ±3.36
Bassoon	[Fuks 1996], Figures 28 and 30, graphic interpolation	2	C2	ff	23.58 ±1.04	pp	12.52 ±0.94	4
			B4	ff	69.17 ±19.09	pp	28.69 ±5.11
Bombardon	[Stone-WH 1874]	1	B2	mf	7.47			8	Measurement given in whole inches H2O
			G4	mf	89.67
Clarinet	[Fuks 1996], Figures 10 and 12, graphic interpolation	2	F3	ff	45.97 ±2.35	pp	28.61 ±2.86	5
			D5	ff	51.95 ±2.91	pp	26.00 ±1.58
			E6	ff	40.35 ±4.49	pp	21.60 ±1.18
Euphonium	[Stone-WH 1874]	1	B2	mf	12.45			8	Measurement given in whole inches H2O
			G4	mf	67.25
French Horn	[Stone-WH 1874]	1	G3	mf	7.47			8	Measurement given in whole inches H2O
			F5	mf	99.64
Oboe	[Fuks 1996], Figures 22 and 24, graphic interpolation	2	C4	ff	51.96 ±4.59	pp	37.97 ±2.72	4
			E6	ff	109.13 ±14.82	pp	53.21 ±0.21
	[Adduci 2011], Table 14	4	D4	mf	41.32 ±4.00			4
			G4	mf	43.80 ±4.94
			C5	mf	44.22 ±4.52
			A5	mf	52.85 ±3.26
Trumpet	[Fletcher-NH 1999], Figures 1–3, logarithmic graphic interpolation	3	C2	ff	53.80 ±13.70	pp	15.30 ±4.10	8
			B4	ff	152.0 ±57.9	pp	58.80 ±13.20
Western Concert Flute	[Fletcher-NH 1975], Figure 1, logarithmic graphic interpolation	4	C4	ff	3.29 ±1.10	pp	1.85 ±0.71	5
			C7	ff	20.03 ±2.82	pp	16.14 ±4.02
	[Coltman 1966], as charted in [Fletcher-NH 1975], Figure 1, logarithmic graphic interpolation	1	C4	mf	1.02			Not charted
			C7	mf	9.16
	[Bouhuys 1965], as reported in [Fletcher-NH 1975], page 233		C4		7.5–13			Not charted
			A6		27–40
	[Montgermont 2008], Figure 4d, graphic interpolation	1	D4	ff	1.60	pp	0.79	Not charted
			D5	ff	4.76	pp	2.58
			D6	ff	9.15	pp	6.63

Note: Intraoral pressure measurements from various sources were converted to millibars, in many cases, by physically interpolating the location of data points. In some cases, the graphs use a logarithmic scale, which needed a non-linear interpolation. Dyn = Dynamic. IOP = Intraoral pressure. Figure = the number of the figure in this article on which the data for the row is charted.

Note: Pressure measurements are for intraoral pressure, unless indicated. Measurements were converted to millibars, in many cases, by physically interpolating the location of data points. Dyn = Dynamic. Figure = the number of the figure in this article on which the data for the row is charted.

Data from this Study

Note: Intraoral pressure measurements across all Native American flutes (N = 71) are grouped by concert pitch into half-octave ranges. n = the number of measurements for that pitch range. RP = reference pitch, concert pitch based on A=440 or, for instruments not tuned to concert pitch, a breath pressure that subjectively produced a good tone.

Note: Intraoral pressure measurements across all ethnic duct flutes (N = 46) are grouped by concert pitch into half-octave ranges. n = the number of measurements for that pitch range. RP = reference pitch, concert pitch based on A=440 or, for instruments not tuned to concert pitch, a breath pressure that subjectively produced a good tone. Measurements were taken as with Native American flutes. Most of these flutes use the fingering to produce the octave not in the second register. In addition, the fundamental note in each of the higher registers was attempted, as high as was possible on the instrument. These pressure measurements in the higher overtone registers were taken by establishing the pitch and then reducing breath pressure slightly to a point where the tone was stable — reference to precise tuning was not used in these higher overtone registers. The mean for each pitch range is taken over measurements at the reference pitch.

Note: Intraoral pressure measurements across all ethnic reed instruments (N = 4) are grouped by concert pitch into half-octave ranges. n = the number of measurements for that pitch range. All measurements were taken on-pitch (mf).

Note: Intraoral pressure measurements across all ethnic reedpipe instruments (N = 12) are grouped by concert pitch into half-octave ranges. n = the number of measurements for that pitch range. Most measurements were taken at the reference pitch (RP), and the reported mean is taken over those measurements. RP is concert pitch based on A=440 or, for instruments not tuned to concert pitch, a breath pressure that subjectively produced a good tone. On one instrument, it was possible to take measurements at RP ± 30 cents and the maximum and minimum values reflect those additional measurements.

Note: Intraoral pressure measurements across all ethnic overtone whistles (N = 8) are grouped by concert pitch into half-octave ranges. n = the number of measurements for that pitch range. One pressure measurement was taken for each note in each register by establishing the pitch and then reducing breath pressure slightly to a point where the tone was stable — reference to precise tuning was not used for this class of instruments.

Note: Intraoral pressure measurements across all ethnic overtone flutes (N = 8) are grouped by concert pitch into half-octave ranges. n = the number of measurements for that pitch range. Measurements were taken at reference pitch (RP) in the lowest note. RP is concert pitch based on A=440 or, for instruments not tuned to concert pitch, a breath pressure that subjectively produced a good tone. Measurements for the fifth note were was taken using the fingering or in the first register, regardless of what pitch was produced. The fundamental note in each of the higher registers was attempted, as high as was possible on the instrument. These pressure measurements in the higher overtone registers were taken by establishing the pitch and then reducing breath pressure slightly to a point where the tone was stable — reference to precise tuning was not used in these higher overtone registers.

Auxiliary Material

This section begins material that is not included in the [Goss 2013]  research article.

Other Breath Pressures

Here are some other related breath pressures reported from various sources:

Lung Flute. The Lung Flute is a medical device for thinning lung secretions. It contains a reed that vibrates in the range of 12–30 Hertz. At those frequencies, mucus has a significant phase change from a viscous to fluid to thinner secretions. Accordingly, the cilia operate to loosen the mucus by making it more fluid. Once the mucus is more fluid, it can be more easily expelled (Lung Flute web site and [Fowler-Hawkins 2004] ).

The lung flute is designed so that sufficient breath pressure is applied by the patient, which causes the vibrations to be “coupled” with the lungs, transmitting the vibration of the reed to mucus in the lungs. The breath pressure suggested “can be about 2.5 cm H₂O” which is 2.45 mBar (in [Fowler-Hawkins 2004]  and [Fowler-Hawkins 2006] ).

A breath pressure of 2.45 mBar is within the range of speaking pressures as well as the measured pressures of the Native American flute. However, the frequency range of 12–30 Hertz corresponds to notes of G-1–B0, about three octaves below what is produced by the lowest Native American flute.

Glassblowing. [Lee-GG 2012] reports pressures as high as 200 mBar for glassblowing.

Wind Playing and Asthma

Playing wind instruments may significantly help asthma sufferers, as described in this is an excerpt from [Watson-AHD 2009], pages 135–136:

There is considerable anecdotal evidence for the beneficial effects of playing wind instruments on childhood asthma, both in the scientific literature ([Marks 1974]; [Gilbert 1998], [Lucia 1994]) and in personal accounts of individual musicians, some of whom have subsequently become prominent professional players. Though it does not cure the condition, playing appears to reduce the symptoms and improve its management. Asthma episodes can be triggered by stress and exertion, so ti may seem paradoxical that wind playing can have a positive effect; however, though playing requries breath control, it does not increase the hear rate the levels typical of even moderate exercise (Tucker, Faulkner, and Horvath 1971). A common breathing exercise recommended for asthma sufferers is forced expiration through pursed lips that in many ways resembles the action required to play a wind instrument. While individuals with asthma may have difficulty in finding the motivation to carry out such exercises conscientiously, they are a natural consequencde of wind playing, and there is a strong inducement to improve breath control and the duration of expiration for musical ends. Children who are initially unable to hold a sustained note for more than a few seconds may be able to extend this to forty seconds or more over a period of months. Of course, in the event of a severe asthma attack it is important to wait until it is completely over before playing again, but audibly wheezing players who are not otherwise in distress may continue ([Marks 1974]). Though there is no psychological element in the origin of asthma as a disease, stress and panic may contribute to the onset and progress of an attack. For young wind players, increased confidence in being able to control their respiration and manage their symptoms may be a significant factor in their improvement ([Lucia 1994]). There is also circumstantial evidence that, over a period of years, increased ventilation of lungs contributes to the correction of barrel- or pigeon-chest deformities in yourn asthmatic wind players who are still at an age where the skeleton of the chest is capable of remodeling.

Using Breath Pressure for Tuning

Along the lines of the breath pressure profile approach to tuning, here are some pictures of a simple system for measuring breath pressures on Native American flutes developed in 2010 by Steve Petermann of Steve Petermann Flutes:

A simple manometer for measuring breath pressures on Native American flutes. Photos courtesy of Steve Petermann, November 30, 2010.