October 27, 2006
Singling out a Tine for Spectral Analysis

I need a break this week, so I'm providing some short tips. This tip is a followup to David Chapman's article, which I talked about last week.

Every sound we hear is made up of many different frequencies of vibration (except for the sound played on the radio when they do a test of the emergency broadcasting system, which is close to a single pure tone - give thanks to God that most sounds have many different notes hidden in them so that we don't have to listen to those tests more often). The specific notes and their relative strengths end up making each instrument sound the way it sounds. David studied the way his kalimba sounded by analyzing each tine of his kalimba, determining how much of each vibrational frequency (or note) was present when he played each tine.

The Hugh Tracey kalimbas sound different still, and we can determine precisely how they are different by doing the spectral analysis thing.

OK, here's the tip: If you want to study the spectral characteristics of a kalimba tine (i.e., using software like Mathematica as David did, or using software like Audacity as I do), make sure to deaden all the other tines. On the Hugh Tracey, when you play one tine the neighboring tines are also excited, as the vibration travels through the bridge structure and makes those nearby tines also vibrate.