Extracting dB values by timestamp

Hi all,

I’m hoping to find a way to extract dB values in spreadsheet form. Is there a function in audacity to output, say, a .csv file with dB values over time using the PC timestamp?

Backstory: I develop automotive Tier 1 accessory OE exhaust systems and our customers have sound pressure level thresholds that we have been trying to evaluate and design around using Audacity. Currently, we calibrate the microphone and then hunt through a spectrogram track looking for hotspots in what we know to be the sensitive frequency range, using the “Plot Spectrum” tool to ascertain the peak in whatever hotspot regions we identify. If we could log dB levels with respect to time, we could sync the data with OBD2 engine data logs to filter the dB data by load, rpm, throttle position, etc.

If Audacity can’t do this, I’d love to hear about any other tool that can. Regardless, thank you contributing to make Audacity an amazing piece of software.


-Matt

Audacity will give you dBFS for each sample so that’s a ship-load of data to sort through but you can [u]Sample Data Export[/u] up to 1 million samples.

If you want dB SPL you’d still have to calibrate.

That’s amplitude data, not spectral/frequency data. (Technically it’s all of the information, but you have to run a Fourier transform to get frequency information in a usable form.)

The tool can be easily modified to handle more samples, but be warned that each character is 1 byte, so there are at lest 8 bytes per sample (depending on the format options), so data from 1 million samples is at least 8 MB. Many tools will freeze or crash when given extremely large data sets.