Methods and apparatus for detecting respiration phases are disclosed herein. An example apparatus for analyzing vibration signal data collected from a nasal bridge of a subject via a sensor to reduce errors in training an artificial neural network using the vibration signal data includes a feature extractor to identify feature coefficients of the vibration signal data. In the example apparatus, the artificial neural network is to generate a respiration phase classification for the vibration signal data based on the feature coefficients. The example apparatus includes a classification verifier to verify the respiration phase classification and an output generator to generate a respiration phase output based on the verification.
