title: Classification of the Excitation Location of Snore Sounds in the Upper Airway by Acoustic Multifeature Analysis.
abstract: Obstructive sleep apnea (OSA) is a serious chronic disease and a risk factor for cardiovascular diseases. Snoring is a typical symptom of OSA patients. Knowledge of the origin of obstruction and vibration within the upper airways is essential for a targeted surgical approach. Aim of this paper is to systematically compare different acoustic features, and classifiers for their performance in the classification of the excitation location of snore sounds.
  
  
  
  Snore sounds from 40 male patients have been recorded during drug-induced sleep endoscopy, and categorized by Ear, Nose & Throat (ENT) experts. Crest Factor, fundamental frequency, spectral frequency features, subband energy ratio, mel-scale frequency cepstral coefficients, empirical mode decomposition-based features, and wavelet energy features have been extracted and fed into several classifiers. Using the ReliefF algorithm, features have been ranked and the selected feature subsets have been tested with the same classifiers.
  
  
  
  A fusion of all features after a ReliefF feature selection step in combination with a random forests classifier showed the best classification results of 78% unweighted average recall by subject independent validation.
  
  
  
  Multifeature analysis is a promising means to help identify the anatomical mechanisms of snore sound generation in individual subjects.
  
  
  
  This paper describes a novel approach for the machine-based multifeature classification of the excitation location of snore sounds in the upper airway.
authors.affiliation: Machine Intelligence and Signal Processing Group, MMK, Technische Universität München, Munich, Germany.
authors.forename: Kun
authors.initials: K
authors.lastname: Qian
authors.affiliation: Institute for Medical EngineeringTechnische Universität München.
authors.forename: Christoph
authors.initials: C
authors.lastname: Janott
authors.affiliation: Chair of Complex and Intelligent SystemsUniversity of Passau.
authors.forename: Vedhas
authors.initials: V
authors.lastname: Pandit
authors.affiliation: Chair of Complex and Intelligent SystemsUniversity of Passau.
authors.forename: Zixing
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Otorhinolaryngology/Head and Neck SurgeryTechnische Universität München.
authors.forename: Clemens
authors.initials: C
authors.lastname: Heiser
authors.affiliation: Clinic for ENT Medicine, Head and Neck SurgeryAlfried Krupp Krankenhaus.
authors.forename: Winfried
authors.initials: W
authors.lastname: Hohenhorst
authors.affiliation: Clinic for ENT Medicine, Head and Neck SurgeryCarl-Thiem-Klinikum Cottbus.
authors.forename: Michael
authors.initials: M
authors.lastname: Herzog
authors.affiliation: Institute for Medical EngineeringTechnische Universität München.
authors.forename: Werner
authors.initials: W
authors.lastname: Hemmert
authors.affiliation: Department of ComputingImperial College London.
authors.forename: Bjorn
authors.initials: B
authors.lastname: Schuller
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D001314:Auscultation / Q000379:methods*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D006801:Humans; D000069550:Machine Learning; D008297:Male; D008875:Middle Aged; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012137:Respiratory System / Q000503:physiopathology*; D012680:Sensitivity and Specificity; D020181:Sleep Apnea, Obstructive / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012913:Snoring / Q000175:diagnosis* / Q000503:physiopathology; D013018:Sound Spectrography / Q000379:methods*