[Harp-L] Re: Comb Debate Revisited

["Brendan Power" <bren@xxxxxxxxxxxxxxxxx>]

BluzeHarp said: "That said... and without changing anything about the tests,
an audio 
recording would be nice to have."

That's already planned, Chris. Here's the summary once more (with a bit of
extra detail), for anyone who didn't see the original post:
------------------
-----------------

THE COMB DEBATE REVISITED: Player, Close Listener & Spectrograph Test
Co-Conducted by Brendan Power & Vern Smith. Custom combs supplied by Chris
Reynolds

The aim of this test is to see what can be discovered about the sounds of a
harmonica with different comb materials, when listened to up-close under
controlled conditions by three parties: 1. Players 2. Close Human Listeners
3. Microphone and Spectrograph. One issue we hope to shed light on is "Can
the player perceive differences in comb materials?" The test is NOT aiming
to prove that right or wrong, simply to gather useful data for those who are
interested in this question.

In doing the testing, we will record spectrograph images of many common comb
materials, and there could be some interesting ancillary data (eg. possible
tonal differences between embouchures: Tongue Blocking vs. Lip Pursing vs.
U-Blocking).

We will use only one set of diatonic reedplates and coverplates on all
combs, from a Hohner Marine Band Deluxe. Vern has made a special bracket
which will enable fast comb changes and mask the varying weights of the
different combs. The comb smell/feels will be masked so that the different
materials cannot be sensed by lips/tongue. The harps will be cleaned with an
alcohol wipe between each test.

We will be testing eight materials which are commonly used in diatonic
harmonica combs: Pear Wood, ABS Plastic, Diamondwood, Corian, Acrylic,
Brass, Bamboo, Aluminium Alloy. Aside from the stock Hohner combs, the
identically sized/shaped custom combs will be made to exacting
specifications by Chris Reynolds. They will be available for sale after the
test.

There will be six test players. They will be blindfolded and wear ear
mufflers between each test (so they cannot listen to the other testers
before/after their test). They will be respected names who have different
styles and embouchures (tongue block/lip purse/U block). For the
spectrograph readings, two single test tones of 3 seconds each will be taken
for each comb: a blow and a draw on hole 4. For the test playing, each
player will choose a favourite selection of phrases which they duplicate to
the best of their ability on every comb. Each playing test will last 20
seconds. Players will note their impressions immediately after each test, in
isolation. The players will not confer or communicate with each other in any
way during the testing procedure.

The three Close Human Listeners (within 30 cm away from the played harp)
will also be blindfolded for each test, and not permitted to
confer/communicate with each other. They will also note their impressions
immediately after each test, in isolation. 

The impressions will be in the form of a short multi choice questionnaire
relating to commonly used descriptions of sound qualities. The Players/Close
Listeners will be asked "Did the harp sound bright/dull, loud/soft,
full/thin"? The options for each sound choice will be weighted with three
numbers: 1. "Not Very" 2. "Average" 3. "Very". 

After the testing is concluded the results will be correlated with the
various 
comb types and made available. The spectrograph images, test tones and all 
playing clips will also be made available online for anyone to listen to.

An audience is invited to attend the test but must remain silent when each
test is conducted, and must not influence the testing in any way.
------------

Thanks for all the suggestions. As noted, there are various ways to do this
test, and this is the one I've settled on after a LOT of discussion with
Vern and Chris Reynolds. Vern has kindly agreed to help me with this test,
and will likely conduct a differently focussed test of his own in the
future. I hope so!

As BluzeHarp also wisely said "The fun part (isn't that why we play) is much
more in 
the journey/debate. If this test leaves a few lingering questions then we 
will have something more to look forward to."

Indeed! My test is not intended to conclusively decide anything, simply
collect data and impressions in a careful way for the interest of the wider
harp community, to help inform the debate. I hope people at SPAH will attend
the test themselves to verify that we've done everything in as unbiased and
fair a way as possible.

So far for the test players I have Chris Michalek and Dave Barret, as a lip
purser and tongue-blocker respectively. I'm looking for a good U-blocker:
can anyone recommend someone who will be at SPAH?

Cheers,

Brendan Power
WEBSITE: http://www.brendan-power.com
YOUTUBE: http://www.youtube.com/BrendanPowerMusic