Physics Van 3-site Navigational Menu

Physics Van Navigational Menu

Q & A: two-way sound transmission

Learn more physics!

Most recent answer: 08/05/2013
I get the basics about sound waves. But I had a debate while out with friends. Here's the scenario. My friend works in an office that abuts another office. In the next office, she could easily hear two men talking to each other. It was awkward, and we wondered what she could have done about it. I felt that she could simply have spoken and that her voice would follow the same path back to them. Another friend disagreed, saying that the direction she faced would affect how much of her words made it out of her office and back to them. I suspect there are conditions?
- Marcia (age 54)
Storrs, CT

You're approximately right, but not exactly. If we functioned like some devices, using the same transducer to create and detect sound, then there would be an exact relation saying that the transmission goes equally well both ways. Since our ears and mouths are separate devices, in principle there could be a bit of truth to what your friend says. The directionality of our speech and hearing aren't quite the same. At low frequencies, including some of the speech range, however, neither one is very directional. I bet you could be heard with little effort.

Mike W.

(published on 08/05/2013)

Follow-up on this answer.