Background noise in spectrograms

boboq

I just downloaded Electroacoustics toolbox 1.1 and have been playing with the Spectrogram. I am trying to set the display to the old fashioned black on white but find that there appears to be a lot of background noise so that is is hard to  see the formants on the spectrogram clearly. I am using a USB microphone but the display with that is not a whole lot clearer than what I get using the built-in mic on my MacBook Pro.

I was wondering if there is a setting I am missing that would allow me to filter the input a bit so that I could display a clearer signal.

Thanks in advance. This is a great program!

Bob Q.

benfaber

Bob,

If you click on the Scale tab, you will see the Ceiling and Floor controls.  If you increase the floor, you should be able to eliminate a lot of the low-lovel noise in the spectrogram image.

Ben

benfaber

I forgot to mention that using different data window types can also affect the amount of spectral leakage, which may also clear up some of the unwanted noise.  I would recommend trying a Hann (hanning) or Rife-Vincent window.

Ben