When Dr. Sami Simons was starting out as a doctor, an older colleague told him something that stuck with him: the voice sounds different when someone is having an asthma attack. Years later, Simons and his team at Maastricht University in the Netherlands have turned that old observation into a modern tool that could save lives — using nothing more than a smartphone.
A new study published in ERJ Open Research found that a mobile phone app can detect when people with asthma or chronic obstructive pulmonary disease, known as COPD, are about to have a flare-up. These flare-ups, also called exacerbations, happen when symptoms like difficulty breathing, coughing, and chest tightness suddenly get worse. Without quick treatment, they can become dangerous.
The research followed 73 patients — 38 with COPD and 35 with asthma — over 12 weeks. Each person downloaded a special app and recorded themselves speaking every day. They would hold a long "a" sound, then read a short text or answer a question. The app analyzed subtle changes in their voice.
What the researchers discovered was striking. As soon as a flare-up began, patients' voices changed in measurable ways. The pitch became unstable, they paused more often, and the overall voice quality turned what Simons described as "breathier" and "rough." The reason, he explained, is that when the airways tighten during a flare-up, less air passes through the vocal cords. This weakens the normal vibration, making the voice sound different.
The implications are significant. Currently, when someone with asthma or COPD feels their symptoms worsening, they often have to wait for a doctor's appointment or travel to a clinic for testing. That delay can mean prolonged suffering and, in serious cases, worse outcomes. But if people could record their voice each morning and get instant feedback, they might catch a flare-up on day one — the very first day symptoms start.
The app, called TACTICAS (short for Telemonitoring for Asthma and COPD Through voICe AnalysiS), was built together with patients and a technology company called Zana Technologies. It is still only available for research purposes, but the team has created a website where people can learn more and even donate their voice recordings to help the project grow.
Building on their findings, Simons and his colleagues have gone a step further. They have developed machine learning algorithms — a type of artificial intelligence that learns from patterns — that can now predict a flare-up up to three days before symptoms even appear. The team is testing this technology in two new studies: the VOCAL study in Brazil and the SPEAK study in the Netherlands.
If the results hold up, people with asthma or COPD could one day simply speak into their phone each morning. The app would listen for early warning signs, alert them to contact their doctor, and maybe even prevent a trip to the emergency room altogether.
"The voice is different during a flare-up," Simons said. Now, thanks to this Dutch research, that simple fact might become a powerful tool for millions of people worldwide.