Breath sounds are an important part of respiratory assessment and are usually assessed by the respiratory team.
| Sound | Characteristic | Signs of |
| Wheezing | Whistling sound, generally heard on expiration | Asthma and airway obstruction |
| Stridor | Snoring sound heard on inspiration | Typical of obstruction, sputum plug or foreign body, anaphylactic reaction |
| Crackles | A crackling or popping sound | Collapsed alveoli popping open on inspiration |
| Rhonchi | Snoring or rattling sounds | Fluid partly blocking the bronchi; generally heard on expiration |
| Pleural friction | A grating or rubbing sound heard on inspiration and expiration | Indicative of pleural inflammation |