Like everyone else who saw this article, I promptly downloaded the app and started using it.

I could close my eyes and identify each of these sounds:

The subway
The trolley
The bus
The Northeast Regional Amtrak
The Acela (Amtrak)
The regional rail
The freight trains

And that’s just transport and that’s just what I hear in one stretch of my morning loop. Meanwhile, I walk everywhere and can tell you the sound of exactly one bird: a cardinal. Worth thinking about.