What Might the Trombone Teach Us About the Singing Voice?-A Tutorial Review.

The trombone and the male voice cover similar frequency ranges and, at a physical level, the basic anatomies of the voice and the trombone show some qualitative similarity: both have two vibrating flaps of muscular tissue (the vocal folds and the trombonist's lips, respectively), and in each case, these are loaded acoustically by resonant ducts both upstream and downstream. There are also large differences. For example, the downstream ducts differ in length.

'Warming up' a wind instrument: The time-dependent effects of exhaled air on the resonances of a trombone.

To study the effect of 'warming up' a wind instrument, the acoustic impedance spectrum at the mouthpiece of a trombone was measured after different durations of playing. When an instrument filled with ambient air is played in a room at 26-27 °C, the resonance frequencies initially fall. This is attributed to CO in the breath initially increasing the density of air in the bore and more than compensating for increased temperature and humidity.

Trombone lip mechanics with inertive and compliant loads ("lipping up and down").

Trombonists normally play at a frequency slightly above a bore resonance. However, they can "lip up and down" to frequencies further above the resonance (more compliant load) and below (inertive load). This was studied by determining the pressures, flows, and acoustic impedance upstream and downstream and by analyzing high-speed video of the lips.

Acoustic dissipation in wooden pipes of different species used in wind instrument making: An experimental study.

In this study, the acoustic dissipation is investigated experimentally in wooden pipes of different species commonly used in woodwind instrument making: maple (Acer pseudoplatanus), pear wood (Pyrus communis L.), boxwood (Buxus sempervirens), and African Blackwood (Dalbergia melanoxylon). The pipes are parallel to the grain, except one which forms an angle of 60° with the fiber direction.

Laryngeal flow due to longitudinal sweeping motion of the vocal folds and its contribution to auto-oscillation.

Analysis of published depth-kymography data [George, de Mul, Qiu, Rakhorst, and Schutte (2008). Phys. Med.

Relationships between pressure, flow, lip motion, and upstream and downstream impedances for the trombone.

This experimental study investigates ten subjects playing the trombone in the lower and mid-high range of the instrument, B♭2 to F4. Several techniques are combined to show the pressures and the impedance spectra upstream and downstream of the lips, the acoustic and total flows into the instrument, the component of the acoustic flow due to the sweeping motion of the lips, and high speed video images of the lip motion and aperture. The waveforms confirm that the inertance of the air in the channel between the lips is usually negligible.

Producing undistorted acoustic sine waves.

A simple digital method is described that can produce an undistorted acoustic sine wave using an amplifier and loudspeaker having considerable intrinsic distortion, a common situation at low frequencies and high power. The method involves, first, using a pure sine wave as the input and measuring the distortion products. An iterative procedure then progressively adds harmonics with appropriate amplitude and phase to cancel any distortion products.