Human Identity Verification based on Heart Sounds: Recent Advances and   Future Directions
  Identity verification is an increasingly important process in our daily lives, and biometric recognition is a natural solution to the authentication problem.   One of the most important research directions in the field of biometrics is the characterization of novel biometric traits that can be used in conjunction with other traits, to limit their shortcomings or to enhance their performance.   The aim of this work is to introduce the reader to the usage of heart sounds for biometric recognition, describing the strengths and the weaknesses of this novel trait and analyzing in detail the methods developed so far by different research groups and their performance. 
Francesco Beritelli and Andrea Spadaccini
cs.CV stat.AP