harmonic vs. inharmonic sounds

["Ferguson, Sarah Hargus" <safergus@xxxxxx>]

Hello list - I feel really silly asking this, but I can't seem to dig up
a straight answer to this question. 

When I present complex sounds to my Physics of Speech class, I present
different classifications: periodic vs. aperiodic, harmonic vs.
inharmonic, continuous vs. transient, etc. One of the tasks the students
will have in homework is to determine whether a given sound is harmonic
or inharmonic. I tell them a sound containing energy at 200, 300, 400,
500, and 600 Hz is harmonic because all of those are integer multiples
of the same fundamental (which happens to be missing). 

I have two questions:

1) Is this actually correct? 
2) If so, it seems to me there must be some constraint on which
harmonics of the fundamental are there. In the example I gave above,
I've had students say "Couldn't the fundamental be 50 Hz? Or 25 Hz? Or
even 1 Hz?" Is there a rule I can give them? 

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 
Sarah Hargus Ferguson, Ph.D., CCC-A
Assistant Professor
Department of Speech-Language-Hearing: Sciences and Disorders 
University of Kansas 
Dole Center 
1000 Sunnyside Ave., Room 3001 
Lawrence, KS  66045
office: (785)864-1116
Speech Acoustics and Perception Lab: (785)864-0610 
http://www.ku.edu/~splh/ipcd/Faculty/FergusonBio.html