Have you ever tried to measure the speed of the train which is slowing down? Measuring the frequency of the Himalayan Singing Bowl is a similar exercise. The reason – each singing bowl produces multiple frequencies and hence trying to measure one frequency and giving it a “note” is similar to applying the Newton’s law into the space beyond the earth !!
(For background, we use singing bowl in sound healing and its multiple harmonics enable brain-wave entrainment and enables the mind/body to achieve deep rest, facilitating the healing process.)
Spectrum Analysis of a Singing Bowl’s Sound:
Let me share a spectrum (in simple words, the frequency spectrum indicates the amplitude of each frequency present in the sound sample). If you see the spectrum, it is clear that it has three very distinct frequences present. In fact, the pattern is just a sample since this entire pattern also moves at a specific frequency. In other words, the singing bowl produces multiple frequencies or overtones.
What is the “note” of the bowl?
It is common practice to assign a “note” to each bowl. While there is a reason by this is done, it is entirely a left brain exercise if we use that as “the only basis” to judge/select/use the bowl. For example, if we use a commonly available guitar tuner app to measure the note of the bowl (whose spectrum is shown above), it shows “A” at ~110 Hz (somewhere around the first peak shown on the spectrum). As you can see, by assigning a pitch, we are “assigning” the bowl to be dominantly creating the sound represented by the first peak (essentially ignoring that the bowl also generate at least 2 other very strong frequencies beyond 110 Hz).
In short, I hope it is clear now that assigning the note to a singing bowl is a very “vague” exercise and does not represent the real capability of the sound produced by the singing bowl. Specifically, when we are talking about the impact on the brain wave through entrainment, this “note” based representation of the bowl is misleading. In reality, the bowl has first peak at about 110 Hz, the second one at about 330 Hz and third one at about 660 Hz. To conclude, this particular bowl has a low frequency, a mid frequency and also a high frequency.
Another example for getting better perspective:
The analysis below is using a bowl that was marked note “B” when I procured it. You can clearly see at least 3 peaks (if you see the waveform in real time, the entire waveform moves up and down – indicating a very low frequency also present).
The table below captures the frequencies of the same bowl (Courtsey: WAVANAL). It is clear from both the chart (above) and the table (below) that the sound of this bowl contains multiple frequencies ! In future articles, we will learn more about these frequencies and its relationships with the sound of the bowl(s).
Hope by now it is clear that assigning a “note” (and only one “note”) to a bowl is similar to applying the Newton’s law in outer space.
Copyright © Gunjan Trivedi
(Feel free to re-use, with prior permission of the author via firstname.lastname@example.org)