Acoustic emission type | Threshold (dB) | Sensitivity | Specificity | PPV | NPV |
---|
Low-frequency | 0.863 | 69.6% | 54.7% | 14.7% | 94.1% |
Broadband | 11.04 | 75.1% | 62.9% | 18.5% | 95.7% |
Subharmonic | 0.499 | 74.5% | 64.4% | 19.0% | 95.7% |
- Threshold values (in dB relative to the measured noise floor) yielding maximum sensitivity and specificity, with corresponding sensitivities, specificities, positive predictive values (PPV), and negative predictive values (NPV), using data from 18 trials.