When stimulated by radio waves, the elements emit distinctive signals in a magnetic field. (okyanos.com)
Sensitive microphones on the ocean floor off Australia picked up a distinctive signal at about the time that the Boeing 777 aeroplane is believed to have crashed in the Indian Ocean. (scientificamerican.com)
When subjects encountered a sentence with an unexpected grammatical error, EEG readings picked up a distinctive signal: The voltage in an area of the left brain briefly dropped. (discovermagazine.com)