Expert: Paul Soderman - 1/12/2009

Question
QUESTION: Sir,
Do you know whether or not the relationship between sonic boom overpressure and the PldB (on the ground) is linear?  If it is not linear then do you know the relationship between them?

ANSWER: Steven
Can you tell me what PldB is ?  I have seen a lot of acoustic parameters, but not that one.  Incidentaly,a sonic boom is a nonlinear phenomenon.  But I think you are asking me if there is one-to-one relationship between a sonic boom and some acoustic parameter.
Paul

---------- FOLLOW-UP ----------

QUESTION: Yes sir, I can.  I am sorry I didn't define that in my original question.  PldB stands for Perceived Loudness Decibel, it is just a measurement of loudness.  I believe that it is only slightly different than dB.

Answer
Steven
Loudness is a subjective measure that depends on human perception of noise level.  Although we know that an increase in sonic boom intensity causes an increase in loudness, the correlation could very well be nonlinear.  The human brain is not exactly linear.  There are many studies of this problem published during the days of the Supersonic Transport development.

Incidentally, your last sentence is a little off. dB is short for decibel, so PldB is measured in units of dB by your definition and is not slightly different.
Paul