Using concentrated spectrogram for analysis of audio acoustic signals

The paper presents results of time-frequency analysis of audio acoustic signals using the method of Concentrated Spectrograph also known as "Cross-spectral method" or "Reassignment method". Presented algorithm involves signal's local group delay and channelized instantaneous frequency to relevantly redistribute all Short-time Fourier transform lines in time-frequency plain. The main intention of the paper is to compare various guitar playing techniques including legato, staccato, vibrato, glissando, slide and bending. Additionally, the advantages of concentrated spectrograms especially high energy concentration in comparison with classical spectrogram based directly only on Short-time Fourier transform are presented. Moreover, the vibrato playing technique is considered also for another musical instruments: flute and violin.