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I was able to display an acoustic data in Matlab using Signal Anaysis tool box but I have little challenge in converting that into dB. I'm really new to this kind of processing. Is there someone you can help with please? I also intend to remove 58 dB from the resulting signal. I have the data with me and I can attach it if that might help. Thanks

Paul R
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Ali Isa
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    Please show what have you done so far. – iled Feb 21 '17 at 22:55
  • Possible duplicate of [MATLAB sound generation with increased dB-value](http://stackoverflow.com/questions/10013627/matlab-sound-generation-with-increased-db-value) – Paul R Feb 21 '17 at 22:55

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dB is a ratio, not an absolute value. Typically you might express something as dB relative to some reference, e.g. "dB re full scale", or "dB re 1V". The dB value is calculated as:

db = 20 * log10 ( V / V0 )

where V0 is the reference and V is the value of interest.

Using the above value, your requirement to "remove 58 dB" translates to multiplying your current values by 10 ^ -(58 / 20) = 0.001259.

Paul R
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