Audio tool for displaying spectrogram in real time using Sphinx-4

The iSound is a program that was built with help of the CMU Sphinx-4 system. It is a part of the thesis at the Faculty of Mathematics, Natural Sciences and Information Technologies from Koper, Slovenia. Its main goal is real-time audio signal visualization, also known as spectrogram or sonogram. Which means, that it allows observation of the sound.


This property could be useful in many areas, such as: phonetics, animal sounds analysis, music, sonar/radar, speech processing, seismology, etc. Additionally, it has included few features into basic spectrogram drawing, which made the application more useful. That features are: image freezing, zoom control, signal frequency display, resizing, changing of the color schemes and contrast adjustment.

Compared to the other programs with similar functioning it gives promising results of the CPU, memory and graphics usage. Tests were made on Windows XP, Windows 7, Linux ubuntu and OS X Lion. You can find full test results in the diploma, on page 40.

Author’s comment: “For future work i plan to publish research work as an article in the journal. Currently I’m working on idea, how to use similar technologies and develop a tool, which can help persons with hearing handicap.”

Find useful information about the project, at the author, Irman Abdić’s web page: