else's conversation in the room. More people these days are taking their cell phone conversations outside, away from other people, which is nice.
I, being the grumpy old man that I am, still find listening to them, even if it is just a snippet, annoying. And then there is the other side of the coin: what if you are having a conversation that you do not want everyone else to hear? What can you do, besides run and hide?
I think technology may be able to provide a solution: noise canceling cell phones. Noise canceling is used on some Turbo-prop airplanes. There are noise cancelling headphones available. I am thinking that a speaker on the opposite side of the microphone from the cell phone user's mouth could be used to cancel the sound of their voice for anyone else in the vicinity.
Some other people also have ideas for cell phones.
I and others have noticed that people tend to talk more loudly when then are on the phone, and I have been wondering why that is. I have come up with a couple of ideas. One is that they are compensating for the ambient noise level. The ambient noise where the two parties to a phone call are is almost by definition going to be different. If you standing next to someone, the ambient noise level is the same for both of you, so you can filter out the background noise to pick up the conversation. On the phone, you have two sets of background noise to deal with: yours and the other person's. By speaking up, you are creating a larger difference between your voice and the background noise, which makes your voice more distinguishable.
The other idea is that by speaking louder, your voice acquires more dynamic range, which makes it easier to understand, regardless of the background noise.
Update December 2016 replaced missing picture.
2 hours ago