Relation between Tension and Y-Axis value

Hi, there is a matematical relation beetween the tension of the output of a microphone read by matlab and the value on the y axis of matlab plot? if in y-axis of matlab i read 5, it means 5V of output of microphone? thanks Paolo

Answer 1

[Walter Roberson]

There can be, but it depends upon how you are doing the reading of the data, and what device you are reading from. It is not uncommon that the readings would be normalized to [-1, +1) or [-1, +1], or to 0 meaning no signal and ((2^bits)-1) meaning maximum signal that the ADC is configured to measure.

Usually when you want to know this kind of information, you also need to know the microphone pressure to signal curve. Most often the best way to get that is to calibrate with a reference source.

Answer 2

[Paolo Rossi]

hi! i save a .wav file on the PC and than i import it with wavread command, may be it's simpler calibrate it with reference..... thanks