Magnitude of data aquired by PC sound card

[p62mopar]

Hi, I'm aquiring data from a microphone connected to the PC sound card. I'm using 'Sound Input Read.vi' with 'Spectral Measurements Express VI' for graph data.

My question: ¿What is the unit for the Y axis (amplitude): adimensional, Pa, Volts?

I think is adimensional cause 'Sound Input Read.vi' convert data from sound card to (1,-1) values without know what hardware is connected to his input... but I'm not sure.

[sendia]

Hello,

Data from the sound card are normalized so yes, the range is from -1 to +1 (using Double data types) or + - absolute range