The sense probe was used as a control and did not produce a signal.
Her telephone number produced a busy signal all night, and it is not clear if she has been released yet.
Nature had a thousand ways of producing a signal with some repeating pattern.
The signal produced is dependent on the equipment used to master the disc.
His call to Warrendale's home produced a busy signal, which was repeated when he tried it again.
Neither of us can get our routers to produce a usable signal.
It has the disadvantage of producing a comparatively weak signal.
And yet, at least higher plants are able to produce electrical signals, even if they do not use them in the same way animals do.
In such a relationship, the bacteria do not respond to the availability of nitrogen, but to signals produced by the plant.
In order to produce separate signals, individual prey must be about five body widths apart.