I'm pretty sure you could measure this with a mobile phone app, if such a thing doesn't already exist. I've already many times used such an app to measure acous

I'm pretty sure you could measure this with a mobile phone app, if such a thing doesn't already exist. I've already many times used such an app to measure acoustics in a room as part of the setup process for multiple brands of home speaker system, they emitted a range of frequencies and presumably measured the result using the microphone.