John Rhodes found a short paper about the subjective impression
of frequency at the web site of Sonic Research Studio, School of
Communication, Simon Fraser University.  The paper, published in
"Handbook for Acoustic Ecology," Barry Truax, editor, is presented
at http://www.sfu.ca/sonic-studio/handbook/Pitch.html  Extracts:

  "The sense of pitch depends on the intensity of the tone, as shown in
the graph; below 1000 Hz, pitch tends to drop with increasing loudness,
and above 1000 Hz, tends to rise.  A tone must have a certain duration
for pitch to be ascribed; if not, it is heard as a click.  The nature
of the spectrum of a complex tone will affect the sense of pitch as
well.  A note rich in overtones will appear to have a more definite
pitch than a sine tone of the same frequency and intensity, for
instance.

  "The pitch of the complex tone will correspond to its fundamental
frequency. ... The change in pitch in percent with loudness for various
frequencies as indicated on the curves (from Olson, Music, Physics and
Engineering, Dover, 1967, p. 251, after Stevens, used by permission)."

Robbie Rhodes