Here is an informal listening challenge to try. Necks were fabricated from four different timbers, but all other details were nominally identical. The necks were fitted in turn to the same banjo pot, and several recordings were made of the same tune. The question now is: can a listener recognise which neck is which?
A set of these sound files has been trimmed to the same short snatch of music in each case. First, you hear these played using necks which are identified by their timber choice. After that, there are 5 files labelled A–E. These contain one example of each of the four timbers, plus a second recording made using one of them. Can you marry these up with the first four sounds? You might want to use your best available audio reproduction option for this task, either headphones or loudspeakers. After you have tried it, you can find the key here. More detail of the experiment can be found here.
If you can hear differences and do at least some identifications correctly, that tells you something — but we need to be a bit careful about exactly what. You may be hearing differences that are specifically caused by the different wood species in the necks, but you might also be hearing differences associated with small differences in the nut grooves, action height or other aspects of setup. Later, in section 7.4, we will meet the example of the lute, where it seems that an important ingredient of the sound quality is caused by a very subtle level of “fret buzz”, contact between the played strings and the higher frets. This example gives a warning against leaping to conclusions about the cause of sound differences.