A subject reports hearing a series of tones he has plotted using a tone generator to 400Hz, 440Hz, and 470Hz. These tones correspond to the piano notes G, b-flat, C#. The reported pattern is a drone with the 400Hz G, alternating up to the 470Hz C#, and often but not always dropping down through the 440Hz b-flat. Other members of the household do not report hearing these sequences. The subject reports no tones in some areas of the environment, but is able to predict where in the house he will hear them. The tones are the first sense data he is aware of on waking. How would one investigate this?

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