Mystery Signal from a Helicopter (2014)
Sox is amazing.<p>I used it about 10 years ago to take raw audio of paintball guns shooting and help pre-process said audio for analysis of shots per second.<p>It was great for a bunch of reasons:<p>- it could so a frequency analysis to show me which frequencies were present in the audio<p>- I figured out there was the frequency of the sound when the ball left the barrel but also a frequency for the gun's firing mechanism<p>- I could then do a bandpass on just the frequency of the ball leaving the barrel<p>- It then let me convert the audio to a numerical format that made analyzing the peaks and valleys much easier in Perl<p>- The end result was I could accurately calculate shots per second given just a raw recording and some processing time