Characterization of failure conditions: false positives and false negatives

Data from Hyfe’s clinical validation trial show that the Hyfe CoughMonitor Suite (CMS) performs strongly across diverse real-world conditions, with accuracy varying naturally from participant to participant. This variability is expected in any acoustic sensing system and reflects two main factors:

1. Individual differences in cough acoustics, and
   
2. The wide range of everyday environments in which participants spent time.

Importantly, the trial included challenging, uncommon scenarios—such as concerts, crowded indoor venues, power-tool use, loud kitchens, open-window driving, and breathing-machine use—so that performance statistics would reflect the full breadth of real daily living, not ideal conditions. These rare environments were “baked in” to the accuracy calculations, making the results conservative and strengthening confidence in Hyfe CMS performance during normal use.

False Negatives

Missed coughs occurred in situations that are not typical for most users, such as:

• Very quiet coughs masked by extremely loud background noise (e.g., choir practices, group singing).
  
• Highly atypical or unusual cough types (e.g., muffled or percussive throat-clear–like coughs that differ from standard cough acoustics).

False positives

False cough detections were linked to a few specific, uncommon sound types:
- Laughter containing glottal bursts
- Non-cough throat clears
- Sharp, explosive household noises, such as dishwashing impacts

These sounds are infrequent in most day-to-day settings, and the algorithm correctly handled them most of the time.

Overall Interpretation

Because Hyfe’s validation trial included high-noise, atypical, and acoustically extreme environments, the accuracy metrics represent a rigorous, real-world stress test rather than idealized performance. In typical home and daily environments—where coughing usually occurs—the CMS performs strongly and reliably, offering clinically meaningful detection accuracy.

Clear labeling ensures that users understand the rare edge cases where performance may vary, but the overall findings demonstrate that the Hyfe CMS is a robust, high-quality cough monitoring system suitable for real-world clinical and personal use.