The Cocktail Party Effect

2016 is over, and many of us attended celebrations of remembrance of the year’s transpiration and resolutions for the year to come. Civilizations around the world have been celebrating the New Year for at least four millennia, but not always in December. Learn more about the history of New Year’s Eve (NYE).

Today, common traditions include attending parties, making resolutions, toasting with champagne, singing “Auld Lang Syne,” and enjoying food (in the United States, it is southern greens, black eyed peas, and cornbread…peas for pennies, greens for dollars, and cornbread for gold). The pop of the champagne cork, toasting to the new year, singing songs and making resolutions all together make a less than accommodating listening environment creating a situation that we commonly refer to as the “cocktail-party” effect.

The cocktail party effect refers to the ability to focus one’s attention a particular stimulus while filtering out a range of other stimuli (i.e., noise). But, how is the brain able to do this?  Recently, Holdgraf et al. (2016) have turned an ear to the neural plasticity of the brain that enables extraction of speech-like features from a degraded input. In brief, they found that the brain emphasizes anything that might be speech-like and that these tuning properties can be improved with experience. The study was performed in epilepsy patients who had electrodes placed on their brain’s surface to track seizures. Using these electrodes they were able to record changes in neuronal activity to speech stimuli. First, a garbled message was presented.  Next, the filtered clear version of the message was presented. Finally, the garbled message was presented again.

Not only, were the participants able to understand the garbled message post the clear message (a simulation often demonstrated in hearing and speech courses), but the neural recording showed nearly the same language-appropriate neural activity as observed with the filtered clear message suggesting a rapid and ongoing alteration of spectrotemporal feature detection and auditory tuning. Future work is needed to translate these findings to improved outcomes for normal hearing and individuals with hearing loss. Rapid tuning shifts in human auditory cortex enhance speech intelligibility.

Stay “tuned” for more in the New Year!

Reference

Sanders R (2016) How the brain extracts meaning from noise. UC Berkley. December 22.