The Flex, explained.
Rayvox founder and Resono inventor, Oren Boder talks you through some of the features of these revolutionary vocal development tools.
Click the stories to popup the video player.

Free Your Voice With Bubbles
Water bubbling technique is a type of semi-occluded vocal tract (SOVT) exercise that involves blowing bubbles through a straw submerged in water. It is highly recommended by medical professionals as a recovery and rehabilitation intervention for intricate muscles of the voice. The technique provides bio-visual feedback from the bubbles, allowing you to see your respiratory output and identify when there's either too much or too little effort applied.
Plus, you also get alternating pressure waves from the bubbles, which creates an internal massage for your vocal muscles that helps with recovery and rehabilitation (and is great as a warmup and cool down too).

Seal the Deal with Every Note
Our uniquely designed mouthpiece creates the perfect seal for your lips, ensuring you have total control over your vocal tract oscillation, enabling the therapeutic "massage effect" for vocal muscles.
With the Resono Flex, you will literally feel your entire vocal tract (including your cheeks) oscillate / pulsate with the alternating pressure provided by the device - that means it's working to unlock the true potential of your voice.

Dive Deep into Vocal Perfection
Take the plunge with our Resono Flex's depth markings! Whether you're a shallow dipper or a deep diver, our precise indicators make it easy to find the ideal water level (and resistance) for your vocal training.
Find your sweet spot and let your voice soar.

Sterilized & Certified for Your Peace of Mind
We're committed to providing safe and reliable vocal training and rehabilitation tools. That's why each Resono Flex comes in a sterilized, individually sealed packet, ensuring maximum hygiene for your vocal training. Plus, our CE certification guarantees quality and compliance with international standards.
Sing with confidence knowing your voice is in good hands.
Trusted by the pros
Our vocal development tools are used by Singers and Professional Voice Users from over 40 countries around the globe, as well as by Broadway, West End, and Television/Film Stars; from shows like Les Miserable, Wicked, Hamilton, Frozen, Phantom of the Opera, Chicago, and so many more!
Science in the press
"Straw phonation not only lowered the onset of normal voice, but also elevated the onset of chaotic voice, indicating a better voice economy and voice control. Moreover, the improved phonatory range demonstrated that straw phonation had the potential to prevent voice users who have high voice demand from voice fatigue and vocal damage."
"We think Semi-occluded Vocal Tract exercises are brill. They have a solid of research behind them and have been helping singers clinically for years. Bringing these into your daily warm up routine, or even more than once per day, will help you to warm that uncooperative little monkey into a beautifully functional instrument in half the time."
"The straw phonation exercise caused positive effects, seen upon voice self-assessment, indicating an easier and better voice upon phonation."
"Narrowing the vocal tract increases air pressure above the vocal folds, keeping them slightly separated during phonation and reducing the impact collision force"

Flex Specs.
The Resono Flex is made from FDA approved food-grade Silicone. It's flexible, durable, and designed to last. And it's dishwasher safe.
Dimensions: 300mm long, c.11mm inner diameter*, c. 20mm outer diameter*, with a 22mm built in mouth piece.
*The Resono Flex isn't perfectly round, so the inner and outer diameters are approximate.
UK Registered Design: #6266698.