Nebulisers and Nebulised 0.9% Isotonic Saline: What every professional user should know by Diarm Scahill

Nebulisers have become increasingly common among singers and other professional voice users, particularly during periods of heavy vocal demand. Some performers won’t go on stage without one, while others question whether they actually work. So, what does the evidence tell us?

Current research suggests that nebulised 0.9% isotonic saline can improve the surface hydration of the vocal folds, reducing the effort required for voice production and promoting more efficient vibration. While the evidence base is still developing, the findings are encouraging for singers and other professional voice users.

What is a nebuliser?

A nebuliser is a device that turns liquid into a fine mist that can be inhaled.

In respiratory medicine, nebulisers are often used to deliver medication directly into the lungs. In voice care, however, the liquid is usually 0.9% isotonic saline – sterile salt water with the same salt concentration as the body’s own fluids.

Unlike drinking water, which improves systemic hydration, nebulised saline aims to increase superficial hydration by moistening the surface of the vocal folds. The two work through different mechanisms and complement one another.

Why does surface hydration matter?

The vocal folds collide hundreds of times every second during speaking and singing. To tolerate this repeated impact, they’re covered by a thin layer of mucus that acts as a lubricant, allowing the tissues to slide smoothly over one another. When this surface layer becomes dehydrated, the mucus becomes thicker and more viscous, making collisions more effortful.

As surface hydration decreases, the vocal folds require greater air pressure to start vibrating. Voice scientists measure this using phonation threshold pressure (PTP) – the minimum air pressure needed to initiate phonation. Research by Verdolini-Abbott and colleagues demonstrated a clear relationship between hydration and phonatory effort, particularly at higher pitches, with dehydration increasing the effort required for phonation. The most likely explanation is that hydration reduces viscosity, allowing the vocal folds to oscillate more efficiently.

What does nebulised isotonic saline do?

Nebulised saline targets the thin layer of fluid covering the vocal folds. By improving this surface hydration, it appears to reduce the viscosity of the mucus, allowing it to spread more evenly and helping the vocal folds vibrate with less effort.

Laboratory research also suggests that isotonic saline changes the physical behaviour of mucus itself, helping it form a more stable lubricating layer. Although these studies weren’t performed specifically on singers, they provide a plausible explanation for the improvements seen in voice research.

What does the evidence show?

Several studies have investigated the effects of nebulised 0.9% isotonic saline in trained singers.

Following experimentally induced laryngeal dehydration, singers who inhaled 3 mL of isotonic saline consistently reported that their voices felt easier to produce, with perceived vocal effort returning to baseline. Neither sterile water nor no treatment produced the same improvement.

A similar study in trained male singers found that both 3 mL and 9 mL doses reduced perceived vocal effort and throat dryness, with no clear advantage of using the 9 mL dose.

More recent work has examined the vocal folds directly using high-speed digital videolaryngoscopy. Researchers reported changes consistent with more efficient phonation, including improvements in vocal fold vibration, aerodynamic efficiency and measures related to vocal fold closure. Together, these findings suggest that improving surface hydration may also improve the efficiency with which the vocal folds vibrate.

How should I use it?

There is currently no evidence-based maximum frequency for nebulising 0.9% isotonic saline. It is reasonable to assume that a dose of approximately 3 mL, typically nebulised over about 10 minutes, is appropriate. It can be used as a single treatment following vocal loading or, in some studies, twice daily during periods of increased dryness.

One point is clear: only use sterile 0.9% isotonic saline. Regular tap water is not sterile and should never be placed into a nebuliser.

Nebulisers also need to be cleaned properly. After each use, wash the medication chamber and mouthpiece or mask in warm, soapy water, rinse if recommended by the manufacturer, and allow the parts to air dry completely. Once a week, disinfect the reusable components. For many devices, this can be done using a diluted white vinegar solution, following the manufacturer’s instructions. Keeping the equipment clean helps prevent biofilms from developing, reducing the risk of introducing bacteria or fungi into the airway.

Like any piece of equipment, a nebuliser is only as hygienic as the person maintaining it.

Where can I get one?

Nebulisers are widely available on Amazon and from some pharmacies, with prices ranging from around £15 to over £100. For nebulising 0.9% isotonic saline, even inexpensive models work well, but just choose one with good reviews.

Use sterile 0.9% isotonic saline in single-use ampoules, such as Physiodose, which are widely available on Amazon. Never use homemade saline or tap water in your nebuliser, as they are not sterile and can increase the risk of infection.

Take-home message

The current evidence suggests that nebulised 0.9% isotonic saline is a safe and promising strategy for improving the superficial hydration of the vocal folds. For professional voice users, its greatest demonstrated benefit is a reduction in perceived vocal effort, with emerging evidence that it also improves the efficiency of vocal fold vibration.

It is not a miracle cure, and it will not replace good vocal technique, sensible vocal loading, adequate systemic hydration or appropriate medical care. However, when used appropriately, 0.9% isotonic saline appears to be a simple, low-risk tool that can help many singers keep their voices functioning more efficiently during periods of increased vocal demand.

Diarm Scahill is a London-based singing teacher and SVI-trained vocologist. Originally trained in science, he later pursued a career in Musical Theatre before undertaking postgraduate studies in Voice Pedagogy. He works with professional singers and actors in the West End, on UK and international tours, at ArtsEd and in private practice, bridging the gap between voice science and performance.

www.diarmscahill.com
Instagram: @diarmvoice

 

References

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Masson, M. L. V., & de Araújo, T. M. (2018). Protective strategies against dysphonia in teachers: Preliminary results comparing voice amplification and 0.9% NaCl nebulization. Journal of Voice, 32(2), 257.e1–257.e10. https://doi.org/10.1016/j.jvoice.2017.04.013

Plec, E. M. R. L., Gama, A. C. C., Souza, B. O., & Santos, M. A. R. (2024). Effect of nebulization on laryngeal parameters: Analysis using high-speed digital videolaryngoscopy. Journal of Voice, 38(4), 970.e1–970.e12. https://doi.org/10.1016/j.jvoice.2022.01.014

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