Am using it regularly now after 50 years of a career !!! Very useful and grateful to have discovered the straw !!! Am stuck in hotel room and getting ready for Bach’s Christmas Oratorio. A marathon for the tenor but less demanding with this useful aid !!!

The so-called straw exercise uses what I call the MBP-impedance as the basis for placement (= optimum balanced resonance). It can help you find the optimal airflow and trunk-support for the double-lipped consonants: M.B.P. But also for the tongue-tip dentals: NDT, as the top of the straw usually leans behind the front teeth where Italian tongue-tip dentals are formed. The optimum balanced resonance after aligning the vowel frequencies with MBP+NDT impedance impels the voice forward (accelerated vibration) resulting in clear vowel and crisp consonant projection. This is called “forward placement” by some Teachers. It can be a source of technical orientation for some singers. The accompanying trunk activity depends on the singer’s natural reflexes or the orientation of his/her Teacher. The teacher could use the principle of buoyancy focusing on girding the loins and trunk (support) for sustained release of air. Or the teacher might use the principle of gravity, focusing more on particular ways of “leaning” (appoggio) as leverage for a sustained release of sound. Some teacher use both principles through multitasking trunk muscles (e.g After inhalation: lower abdominals gird from the outside in and upwards while upper abdominals: lean from the inside out through gravity or Engaging of lower-back muscles according to the school of training).
Pedagogues look for “clear and crisp” resonance by combining the vowels A. E. I. O. U with the MBPNDT (lip ad tongue) impedance. There is a systemized approach in the Sieber Exercises series. These exercises use the syllables da-me-ni-po-tu-la-be in different pitch combinations. The consistent alignment of the formants, frequencies and vibrations represented by the sounds results in a vocal reflex of sustained vibrant sonority. The sound resonates through the expanded pharynx and the head, especially around the eye-sockets (which are huge resonance chambers). This characterizes the elusive process called singing/placing “in the mask”. The “mask” is indicative of the upper half of the face where Italian (Venetian) carnival masks were/are worn. The “placing (= optimum balanced resonance) in the mask” involved this whole process of balancing the upper resonances resulting in clear and crisp vocal projection.
A related process occurs when singing teachers ask to “smell a rose” or “inhale the voice/sound” (inalare la voce), or drink the sound. These terms are meant to trigger feelings of well-being connected to expansion of the resonators (e.g pharyngeal wall-tissue) with the appropriate deeper trunk expansion resulting in a vibrant sonority. Another elusive process is that of the “to smile or not to smile” with mouth corners or “to perk or not to perk” the cheeks. These are both attempts to trigger the process of expanding the pharynx and engaging the zygomatic musculature that accompanies the process. Manipulating a strong buzz directly into “the mask” is also an attempt to imitate the enhanced vibration of projected resonance caused by alignment of the Frontal Impedance formants (MBP-NDT) with vowel sounds.
Of course there is a lot of controversy regarding all the mentioned terms, but once we understand the intentions of Italian-based vocal methods we discover that most terms look for the same result. It takes us back to the primary goal in Italian-based vocal pedagogy: the achievement of expressive sonority idealized by the Italian Singing Masters through methodically objectified exercises.
I cannot stress the importance of the Article on “Openings” which talks about the psychological aspects of finding optimum resonance. Opening up resonance is not just a physical process, there is a whole psychology attached to the sounds we use to express ourselves. So the methodology of balancing registers, exploring new sounds in foreign languages, and finding the “ring” (squillo) of the voice are all attached to the singer’s inner life and must be dealt with accordingly. So besides the straw’s unspoken benefits it is also important to become familiar with the inner state that allows the benefits to occur.