Air sounds may be produced by blowing across or down the embouchure hole, and different combinations of air and pitched note can be used. In the context of ordinary playing, a player can transform a sound from pure pitch to air and back again relatively easily and smoothly.
Air sounds across and into the flute
Air sounds (sometimes also called residual or aeolian sounds) are created through blowing an air stream across the embouchure hole. Air sounds can be produced at varying dynamics, but frequent breaths are required to sustain a loud sound. The pitch is dictated by the fingerings of the flute, although no tone is produced in the normal sense. The air stream can be difficult to control (especially if a sound without any pitched note is required), but different positions of the flute in relation to the mouth may be considered (eg turning the flute away from the mouth, or moving the flute as a whole away from the player). If the flute's position is to move considerably away from the usual playing position, it is necessary to allow time to move to and from that position for the effect to be most reliable. Frequent breaths are needed and amplification may be required.
It is possible to move smoothly from an air sound to a normal tone and back again, or to combine elements of pitch and air in the sound.
Transition from air to pitched note and back again
As above but trilled
With all air sounds, air use is highly uneconomic and breaths are required every few seconds. This can be extremely fatiguing for players, so prolonged passages of air sounds, especially at loud dynamic levels, should be avoided.
Jet whistles are produced by blowing hard down the embouchure hole, producing a pitched sound which contains many harmonics. A loud sound cannot be sustained for more than around a second on the bass flute due to the amount of air used. The lower-pitched harmonics in the bass flute's sound mean that this is a much less dramatic effect than on the C flute, lacking both the range of pitch change and projection. Jet Whistles are most effective using the lowest pitches of the instrument, as a greater harmonic spectrum is available from these notes. It should also be noted that time is required before and after this technique to allow the player to move to the necessary playing position. This is particularly important with the upright bass flute, since the instrument's spike may need to be moved to a new position on the floor to allow the player enough space to fully cover the embouchure hole.
A jet whistle may be modified through changing the flute's position against the lip (ie by rolling out), to bring out the upper partials in the sound. Changing the vowel shape inside the mouth can also have an impact on the type of sound, as well as the pitch, produced.
Generally speaking, jet whistles are more difficult to achieve, and often much less effective, on the bass flute than the C flute, due to the volume and pressure of air required.
A gentle air stream through the instrument produces a much softer effect, but very frequent breaths are needed.
Gentle air stream through the flute
Unlike other wind instruments, it is not practical to breathe in through the instrument on a bass flute, as the breath itself does not travel through the flute. Inwards breath sounds are not naturally particularly noisy, and by creating a deliberately noisy in-breath for musical purposes it is likely that the player will then have to breathe in again in order to have a suitable amount of air to play. The large volume of air needed to play the bass flute means that it is advisable to avoid incorporating controlled breathing sounds into a composition. Players have varying lung capacities and breathing too frequently in a specifically noisy way can easily cause discomfort to the player or hyper-ventilation. As an alternative, it is recommended that one solution to incorproate breathing sounds into a composition if for them to be pre-recorded and used as part of an electronics part.
Notation of air sounds
Air sounds range from breathy pitched notes to blowing down the flute's embouchure hole to create a harmonic 'jet whistle' through the flute. There is no standardised notation for these effects - those shown below are merely suggestions. Ensure all notations are shown in a glossary.
Pure air sounds
Pure air sounds transition to pitch