Interesting experiment. Intuition suggests that the smaller size of
the playback room caused the listener's to demand a higher SPL in
order to recreate the experience of hearing all the combined ambience
& directional cues that would've accompanied a live performance in a
concert hall. But that's just a guess.

(Dick Pierce) wrote in message ...


Some years ago I did an informal but enlightening experiment. I
was given the opportunity of measuring sound pressure levels at
several different positions in audience and at the conductor's
podium, and was able to record a lot of good data. At the same
time, a colleague was recording the concert. The material was
classical orchestral music, Beethoven and the like.

After the concert, there was a party which was attended by a number
of people in the audience along with the conductor. There was a room
where a quite respectable playback system was installed, and we had
the opportunity to play back the concert tapes.

I took the opportunity to conduct an experiement: I asked people
who had attended the concert and were seated close to where my
measurements were taken to adjust the volume control so that it
was as loud as they remembered it during the performance. Remember
that they were not only playing back the same music, they were
playing back THE EXACT SAME PERFORMANCE.

The result were VERY interesting. With but a single exception,
EVERY one of the participants in the experiment adjusted the
volume control so that the sound pressure levels on playback
were SIGNIFICANTLY louder than they encountered during the
performance. And the differences were not subtle, often they
adjusted the volume so it was 10 dB or more louder than they
experienced in the performance.

The ONLY person to get close was the conductor.

The experiment suggests that many people tend to play louder
than realistic sound levels.

This correlates with the tendency of people to overestimate
what the sound pressure of music actually is in a live performance,
especially for classical music.