Hadi Jafari - Faculty of Humanities, Payame Noor University of Qazvin, P.O.Box 34199-14917, Qazvin, Iran
Peyman Jalali - Vibration and Modal Analysis Research Lab, Faculty of Mechanical engineering, University of Tabriz, P.O.Box 51666-14766, Tabriz, Iran
Sina Varahram - Vibration and Modal Analysis Research Lab, Faculty of Mechanical engineering, University of Tabriz, P.O.Box 51666-14766, Tabriz, Iran
Reza Hassannejad - Vibration and Modal Analysis Research Lab, Faculty of Mechanical engineering, University of Tabriz, P.O.Box 51666-14766, Tabriz, Iran

A voice is a sound which is created by vibration of the vocal cords, which means that, the vocal cords approach to each other by passing the air through the larynx and followed by different sounds. This vibration is under theinfluence of the statuses of tongue, teeth and lips, as well as the other effective factors. This vibrating air causes someminor changes around the individual speaker, which is called the voice. Some of the most important procedures in thevoice signal analyzing is the signal processing methods in frequency and time-frequency domains; the most conventional approach in frequency domain is the Fast Fourier Transform (FFT) method, on the other hand the timefrequency signal processing methods can identify the frequency components of the signal and extract its time-varyingcharacteristics; moreover they are effective tools for extracting the information of non-stationary signals. Timefrequencyanalysis methods can be classified into linear and nonlinear categories. The Short-Time Fourier Transformand the Wavelet Transform are the most conventional linear methods. This paper investigates the differences in theenergy levels of explosive consonants in voiced mode and unvoiced mode using the most conventional frequency analysis and linear time-frequency analysis methods; these approaches are very effective and profitable in phoneticscience and biomedical engineering science in order to diagnosing and determining the severity of laryngeal diseasesand brain injuries. Results of this study indicate that the energy level of explosive consonants in voiced mode is more than unvoiced mode; also using Fast Fourier and Wavelet Transforms presents the results in better resolution and better image quality than the short-time Fourier Transform

Explosive consonant, Fourier transform, Fast Fourier transform, Short time Fourier transform,Wavelet transform