The constant influx of water from the outside environment of the cell tells that <u>the environment is hypotonic to the cell</u>.
<em>A hypotonic environment is one with a lower solute concentration than the cytosol. Hence, water osmotically moves from the environment into the cells of the protozoans. The water needs to constantly be removed from the cells, otherwise, they will become turgid and lyse away their contents. </em>
The physical stimulus is the only part of the test that is measureable, and therefore, knowable. The stimulus is our anchor for our estimate of the listener's perception.