natural slap echo

[Harry Bissell]

I guess it depends on how you look at it...
The "receiver" has much higher gain...
and the Transmitter has focused all its "information" in a useful direction...
So signal to noise is excellent...
BUT there is still less signal at the receiver than was transmitted. The sound
can never be louder than the source...
(otoh it would be louder than usual...)
:^) Harry (NOW SHOUTING... now whispering...)

Haible Juergen wrote:

>         >This sounds similar to the well-known "whispering galleries".
> Possibly the
>         >radius of the bowl is at the floor, so that upward-going waves are
>         >re-focused back to the source. It can't be louder than the source,
> of
>         >course, but you could get that illusion since you expect echos to
> be rather
>         >weaker.
>         >
>         >  Ian
>
> I think the most effective whisper gallery has an elliptic shape.
> In that case, when both the speaker and the listener are ideally
> located, the volume should actually be amplified. Why's that ?
> Normally the listener will only get a fraction of the acoustic power
> (the part that is directed to him), while in the ideal whisper chamber
> a great portion of the power that was transmitted in *any* direction
> is focussed on the listener.
>
> In my home town, Nuernberg, there was an opening of a new shopping
> center a few months ago. When you go up the escalator to the highest
> story you can hear what people are talking on the other escalator that's
> going down, even though it's so far away that you hardly can see their
> faces.
> It's a striking experience, even when you're familiar with the simple
> theory behind it.
>
> JH.