Breath Recognizer

An example of a swift class to record sound from the microphone and report whether the user is currently breathing into the mic.

It uses a combination of the average sound level and the peak level to try and remove background noise or spikes.

How to use

Copy BreathRecognizer.swift into your Xcode project.

Code Example

When you create a BreathRecognizer you provide it a threshold and a function to be called when the breathing state changes.

  // Specifty a threshold in decibels (-15 seems to work well for breath detection)
  BreathRecognizer(threshold) { isBreathing in
    doSomethingWithTheNewBreathingValue(isBreathing)
  }

Also see the example in ViewController.swift.

Notes:

• The update function will only be called when the state changes (eg. breathing -> not breathing)
• The recognizer will poll for mic updates every 0.05 seconds, I found this to be reasonable but feel free to mess with this in your project.

Todo:

• Possibly provide a delegate interface for callbacks
• Add more customizability in the timing and weighting of the readings.
• Generalize this to detect different types of sound in addition to breathing (talking, clicking etc.).