Humans’ curiosity and laziness have led to numerous inventions, most of which had seemed to be miraculous in ancient times. In this article we are going to dwell upon one of them – a wonderful ability to ‘see’ the sound, or principle and functions of audio spectrum analyzer.
The graphic representation of the sound waves has been in the scientist’s scope for decades, until the first experiments with light beams, mirrors and vibrating objects were held. The pioneer person in audio spectrum analysis was Hermann von Helmholtz, who has invented first means to estimate the frequency. For this he used hollow glass spheres which were carefully calibrated according to the chosen frequency. Excited by the certain frequency they would vibrate and one could hear this by placing his/her ear to the sphere. It was quite a sophisticated process, although it worked. In the twentieth century the oscilloscope was invented, the first device that provided graphic representation of the sound and uncovered its vibratory nature. Later somewhat similar devices came to the fore – they were based on the superhet radio receiver structure and were named spectrum analyzers. Nowadays these are used to measure and display waves of different nature: optical, audio, sub audio, radio ones etc and are widely used in different spheres as powerful testing equipment.
Audio Spectrum Analyzer in Work
There exist two major types of audio analyzers: the analog and the digital ones. The former can process higher frequencies than the latter, although the digital ones can boast better frequency resolution. Each analyzer type has its advantages, which were combined in the so-called ‘hybrid’’ devices, which use both of them: they apply superhet receiver to detect the higher frequency and convert it to lower one. Afterwards, the digital part of the device provides graphic representation of the outcome using complicated math formula (FFT: Fast Fourier Transformation).
When it goes to output, you will find different graphic formats. Output is very important part of the whole analyzing process, since it is going to be interpreted by the user. If the figures are incomprehensible, the whole system turns worthless. Thus, there exist several main graphic outputs, among which are: X/Y plot (where X axis is for frequency and Y is for amplitude), 3D wireframe or 2D format. The format used for output is a matter of taste, although each solution has its benefits and disadvantages.
It is obvious, that the digital audio analyzers are more convenient comparing to analog ones as they can be integrated into your PC’s software. These are vital elements of the audio recording programs and other kinds of audio soft. They help to estimate, recognize and fix the problem fast. Most of them are quite complicated, although after some practice they become useful tools in audio transforming. Besides personal usage, audio spectrum analyzer equipment is also widely used in telecommunication and music industry. Thus these devices are invaluable tools in many spheres of our lives.