Don Herman posted this information on TM, and I thought it would be important to copy it here as well. My response follows.
Quote:
You might look up the Fletcher-Munson loudness curves, or Steinberg, Montgomery and Gardner's hearing contours, or Davis' equal-loudness contours, or similar. Bet that would go a long way toward explaining "carrying power".
For the uninitiated, the curves relate relative loudness to frequency, and are the basis for many tone controls and loudness switches on stereos, as well as acoustic design for rooms and such. At very high volumes, the curves are fairly flat, but as the volume drops the mid-band sensitivity becomes 10 to 1000 or more times greater than the frequency extremes (that is, we can hear a tone at 3 kHz, about an F four octaves over middle C on a piano, much better than a low bass or very high frequency pitch). Key point: human hearing has a fairly broad peak around 2- 3 kHz, which just happens to correspond to the primary pitch of a baby's cry. Imagine that.
FWIWFM - Don
|
Don,
Wow! I’m certainly going to do a little research to accompany this sound experiment. I think you’ve identified why a sound can be louder close to a player and softer in the hall (the player with a less vibrant, less complex sound), versus a softer sound close to the player and a louder sound in the hall (the player with a more vibrant, more complex sound).
For those players that are playing very loud with a "less complex" sound (i.e. they are generating more of the fundamental sound), the human ear is actually hearing less activity in that 2-3 kHz range, where the ear is most sensitive.
For the player that has lots of harmonic activity in that 2-3 kHz range (a colorful, vibrant sound), they can literally play the fundamental with less volume, and yet the higher harmonics will register more easily for the human ear to hear. This player "projects" more, simply because he or she is taking advantage of this physical attribute of human hearing.
The microphone "hears" this too, which is why a single player with this vibrant sound will stick out on a recording, when they are coupled with players that have less vibrant sounds.
Thanks very much for your post! This is starting to make more sense now!