Investigating the Brain Activity Correlates of Humming Bee Sound during Bhramari Pranayama

Previous research has shown the vast benefits associated with BhP. However, the dynamics of cortical activity in connection with Bhramari sound have not been investigated yet.

To investigate the cortical activity in connection with Bhramari sound.

Humming sound was analyzed with a custom-made nasal device consisting of MAX4466 sensor time synchronized with the EEG setup. We anticipated that the modulation of cortical activity with the humming sound (either of long or short durations) leaves its effects after the Pranayama, which helps to understand the positive impacts of BhP.

30 participants were instructed to perform the BhP for a period of 90 seconds. We proposed to investigate the cortical correlates before, during, and after the BhP through EEG. A custom-made nasal device consisting of MAX4466 sensor time synchronized with the EEG setup was used for analyzing the humming sound.

A paired t-test (P < 0.05) with a Bonferroni correction is carried out to explore the statistically significant difference in power spectral density (PSD) values.

Results show that the relative spectral power in theta band for short humming durations (less than or equal to 9 seconds) was similar on the frontal cortex during and after the Pranayama practice (P > 0.05) in most of the subjects.

In conclusion, for the immediate positive effects of BhP, the humming duration should be kept less than or equal to 9 seconds. A wearable sound recording system can be developed in the future as a feedback system that provides biofeedback to the user so that a constant humming duration can be maintained.