RHYTHMIC SENSORY STIMULATION
If you are a musician, you know the beautiful effects of sound and music. But isn’t it sad that the general public and governments don’t realize its effects on our health? If they would only realize this, then music education and live music in general could be more integrated into everyone's daily living.
There are many incredible effects of tonal music and other vibrations whether or not it is produced rhythmically, especially the effects of vibration and resonance during singing, both within our own bodies and its vibrational effects on others. But for now, I am going to focus specifically on rhythmic sound stimulation.
I've been searching for a scientific explanation(s) as to why I have found rhythmic sound stimulation so powerful, (ie scientific explanations including the social elements, but particularly the required focus and concentration, and the impact of rhythmic sound vibrations) whether instrumentally (including through the drum), through movement, and vocally, but especially during my experiences with Samba Squad more recently, as well as my pre Samba Squad experiences with: Patrick Parson of Ballet Creole (culture, song, dance and drumming of Trinidad and the Ivory Coast), workshops with David Thiaw (drumming and culture of Senegal), workshop with Kwasi Dunyo (culture, song, drum and dance of Ghana), visiting master Djembe drummers from the Ivory Coast (culture, song, and drumming) hosted by Ballet Creole, workshops with COBA (Collective of Black Artists) (song, drum, dance and culture), and Guiomar Campbell (surdo, culture, and songs from Brazil), Jacky Essombe (dance workshops and culture of Cameroon).
Sometimes, it is very challenging to explain because there are so many factors involved such as dynamics, the integration of frequencies from a variety of instruments, DNA, and spirituality. But I thought I'd share a tiny bit of what I've located in my search, in the event you didn’t already know about the effects of 40 hz (similar to a low E. See video below (Dr. Bartel's Tedtalk to hear this sound). It would appear that 40 hz helps all parts of the brain communicate with each other and brings everything into sync (two papers below demonstrate that there may even be benefits for those with Alzheimers).
As musicians we intuitively know that the interconnectedness of drums and other instruments integrate various frequencies and that complex rhythms can create a tremendously powerful effect on the brain and health in general. But narrowing in on one isolated frequency is so fascinating in and of itself. This might explain a small fraction of my positive experiences with sound in general.
A great Samba Squad performance at this link (no doubt there are moments of 40 Hz created by the combinations of instruments).
Science is only a way to prove what we already know from experience. Unfortunately, the general public and policy makers/government want this kind of proof. My understanding is that Indigenous Healers (who use sound) know in intimate detail what science is only now being able to prove through the use of newer technology. The following is only a glimpse at some of the scientific proof.
"There is substantial evidence that coherent 40 Hz neural oscillation is a fundamental frequency of healthy brain activity and of intra-brain communication [8–10]. Further it has been determined that the 40 Hz oscillation is a covariate of cognition and not simply an induced sensory phenomenon . This is important for persons diagnosed with AD since they appear to have lower levels of 40 Hz oscillation than
persons of the same age with ‘normal’ brains . Important for the premise of the present study is the finding that auditory stimulation in ‘normal’ persons can reset the 40 Hz oscillation . More recently, it has been shown that 40 Hz steady state oscillation can be stimulated or “driven” with vibration .
"The quantitative results of the study are encouraging and suggest that 40 Hz stimulation over time can lead to increased cognition. Further studies are needed to confirm this and to assess which if any of the AD groups (mild, moderate, severe) benefit the most from this treatment."
Clements-Cortes, A., Ahonen, H., Freedman, M., & Bartel, L. (2016). Rhythmic sensory stimulation and alzheimer's disease. Nordic Journal of Music Therapy, 25, 17
This paper is referenced in this video talk below at around 10:40 minutes
Here is a recent study conducted by U of Toronto:
Mosabbir, A., Almeida, Q. J., & Ahonen, H. (2020). The Effects of Long-Term 40-Hz Physioacoustic Vibrations on Motor Impairments in Parkinson’s Disease: A Double-Blinded Randomized Control Trial. Healthcare, 8(2). https://doi.org/10.3390/healthcare8020113
Here is another article which talks about an experiment completed by MIT using 40Hz and mice:
And here is what their 40 Hz sounds like (40 Hz = Gamma Wave)
Just to note: tonal frequencies and a 40hz wave are different. Isochronic beats are beat patterns not tones. This means that beats are pulsing on and off 40 times per second which creates a pulse that our brains respond to.