Results Online Test

version française, cliquez ici

On this page you can find the video and the results of the blind online listening challenge (survey).

This test was online from 08.06.17 until 26.06.2017 and was completed by 226 respondents.

Go to this page to see how the test was presented to the public.

INTRODUCTION

1

In 2014 the Leonardo Guitar Research Project (LGRP) conducted its first study using blind and non-blind playing and listening tests. 10 classical guitars made from non-tropical woods and 5 classical guitars made from tropical woods were assessed, using a number of different methods, by 3 guitarists/3 listeners and 2 audiences (66 listeners). Click here for the research report

2

At the beginning of 2017 a new study was carried out, this time using 44 guitars (22 guitars made from tropical wood and 22 guitars made from non-tropical wood). 20 guitar players were involved in the testing of the instruments.

This second study was designed to re-examine the findings of the first study. On this occassion we chose to (a) use a larger number of guitars and players, (b) execute the tests in 3 different countries, (c) test ‘pairs’ of guitars, one from tropical wood and the other from non-tropical wood, made by the same builder. (This had not been the case in the first study).

Click here for the report.

3

For this online blind test we employed some of the guitars that had been used during the second study. This time, however, the listening test was carried out using an online survey. Over a two week period 226 people participated in the test.

Go to this page to see how the test was presented to the public.

MATERIAL

The audio used for the blind online test:

Awareness

Question 2: If you had NOT known that there were several guitars in the track, would you have noticed it ? (*this question requires an answer)

Answers:

Perceived guitars

Question 3: How many guitars did you perceive ? (*this question requires an answer)

• Average number of perceived guitars over 226 respondents: 5 (out of 16)

Transition time points

Question 4 : If you perceived more than one guitar, please tell us where the transition(s) between the guitars took place. Note the transition time point(s) (when one guitar follows another) in the box below. For example, if you detected 5 guitars you need to fill in 4 time points, separating them with a slash, e.g. 0:28 / 0:56 / 2:16 / 2:56 (this question can be skipped)

• 80 respondents (out of 226) provided time points / 146 skipped the question

• 8 respondents failed to provide the information in the form requested

• 72 respondents noted a total of 420 transition time points (average: 5,8 time points out of 15)

• Total number of correctly detected time points over 72 respondents = 312 (average: 4,3 time points out of 15)

N.B.: a margin of error of 2 sec. before and 2 sec. after the actual second where the transition took place was applied.

• Total number of correctly detected time points excluding the margin of error = 135 (average: 1,8 time points out of 15)

• Total number of wrongly detected time points out of 420 (i.e; where no transition took place) = 108.

Nature of the guitars (T or NT)

Question 5 : Can you distinguish the tropical wood guitars from the non-tropical guitars? this question requires an answer

Answers:

Question 6 : If you answered YES to question N° 5, please tell us the nature of the guitar (T= tropical; NT=non-tropical) according to the order in which you detected them (for example, if you detected 5 guitars: T, T, NT,T, NT). This question can be skipped.

• 29 of the 226 respondents answered / 197 skipped

• 6 respondents failed to provide the information in the form requested

• 23 respondents provided the information in the form requested

• Total number of identified natures (T or NT) by the 29 respondents = 119 (average: 4)

• 9 identifications correctly matched the nature of a guitar with its corresponding timeslot (transition points)

• 110 identifications failed to correctly match the nature of a guitar with its corresponding timeslot. Either the timeslot was

correct but the nature was wrong, or the timeslot given encompassed 2 or more guitars.

The survey pdf with the raw data, graphs and all comments can be seen or downloaded by clicking here.

(mail addresses of participants are left out)

Supplementary findings concerning the transition time points and the builders

The 16 guitars played on the track alternated throughout according to their nature (T/NT; T/NT etc.) with a total of 15 transition points. Because the guitars were presented in pairs according to their builder, there are also 7 transition points between the different builders' guitars. (These 7 points mark the transition between one builder's NT guitar and the following builder's T guitar). The results show that the average number of transitions detected between the guitars of different builders was higher than the average number of transitions detected between the T and NT guitars of individual builders.

For example; transition 6 (between builder 3 and 4) was detected by 51 respondents. The following transition - between builder 4's two guitars - was only detected by 3 respondents.

All correctly detected time points were compiled into an excel file which was used to make a graph showing the results per transition time point and guitar builder.

CONCLUSIONS

• All 216 respondents perceived combinations of several guitars (including both T’s and NT’s) as being ONE guitar.

• In this test it was very difficult to differentiate one guitar from the other, and virtually impossible to distinguish between

guitars made from tropical wood species from those made from non-tropical wood species.

• Although several people demonstrated outstanding listening abilities (by indicating 7, 8 to 9 correct transition time points),

the ability to detect the nature of the guitars was notably less pronounced.

• This test shows that the distinctive sound qualities and the supposed nature of T’s and NT’s were not distinguishable one

from the other.

• This test implies that neither group (Tropical or Non-Tropical) possesses inherently distinctive, readily identifiable sound

qualities.

• Indeed, as there are clearly more time points detected between T’s and NT’s made by different builders than time points

between T’s and NT’s made by a given builder, it would appear that the builder may have a more pronounced effect on

differences in sound quality than the wood species used for back/sides, bridge, fingerboard and neck.

We should, however, exercise caution as some respondents indicated in their comments that they were able to detect

transition points based on "clicks" caused by editing rather than on a perceived difference in sound quality between guitars.

We are still in the process of analysing whether or not there were more detectable "clicks" or other editing phenomena

between different builders than between guitars from the same builder.

• Furthermore, if we consider other studies on this subject (see extra info), the question has to be asked as to whether the

woods for back/sides, bridge, fingerboard and neck are really as important as has been previously assumed.

DISCUSSION

.If you have any concerns or comments about any aspect of this study, please take contact with leonardo.guitar.research@cmbpuurs.be

EXTRA INFORMATION

• Click here to read the 71 comments on the test (before the results were published )

• See the results of the LGRP studies Phase#1 and Phase#2

• All 16 guitars were subjected to tests (acoustic signature) by François Gautier, Professeur en Acoustique/vibrations

Laboratoire d'Acoustique de L'Université du Maine. The report of that study will be published later.

• Other complementary online tests, using steel-string guitars, that can be completed HERE !

• Video with 12 steel-string guitars of the same model in one song.

Fabien Degryse plays 'in my solitude", Duke Ellington.

The audio of this video was used to carry out 2 audience tests. One in Rome (It) and one in Le Mans (Fr).

The public was asked to listen very attentively to the audio. The following questions were then asked:

• Did you notice anything unusual during the track ?

• Who perceived more than one guitar in the recording ?

• How many guitars did you perceive ?

Almost all listeners on both occasions thought that they had been listening to one guitar.

• Gaëlle Solal plays the 'Newspaper Guitar' / Choro N°1 - H. Villa Lobos

This guitar was made by Luthier Walter Verreydt within the framework of the Leonardo Guitar Research Project.

A modern take on an experiment by Antonio de Torres, the back and sides of this guitar were made by gluing together 40 layers of newspaper using a mold. It seriously raises the question as to how much the materials used for backs and sides contribute to the overall sound of an instrument.

You can send your comments to leonardo.guitar.research@cmbpuurs.be

Thanks !