Spek

Spek is free software available for Unix, Windows, and Mac OS X. It Supports Popular lossless audio files formats, uses multiple threads for faster analytics, ultra-fast signal processing, and a high n number of frequency bands for the best spectrogram quality; spectrograms can be saved as images with drag and drop support.

Spek is a lightweight windows application whose purpose is to help you build the spectrogram for an audio file in order to analyze the frequencies comprised in a sound. The layout is intuitive enough to be configured without having to consult a help manual or watch online tutorials, the program uses the GNOME platform, which includes the Lib, GTK+, Cario, Pango, as well as the FFmpeg Libraries.

Spek was desinged with an overall simplicity in mind, so it doesn't comprise many configuration settings; you are allowed to upload the audio files into the working environment using the built-in browse function or drag and drop operations. During our testing, we noticed that Spek carries out a task quickly and no errors showed up throughout the entire process; it is not quite friendly with system resources, so the overall performance of the computer may be hampered.

To sum things up, speak offers a simple yet efficient software solution when it comes to helping you generate spectrograms it can be easily installed and configured by all types of users regardless of their experience level

Spek offers ultra-fast, multi-threaded analysis for high-quality spectrograms of audio files across various formats.

• Support all popular lossy and lossless audio file formats thanks to the FFmpeg libraries
• Ulta-fast signal processing uses multiple threads to future speed up the analysis
• Shows the codec name and the audio signal parameters
• Allow saving the spectrogram as an image file 
• Drag and drop support, associated with common audio file formats
• Translated into 19 Languages