Please recall the last time you were attending an event in crowded places. Perhaps you went out for a party, or sipping a glass of coffee in a busy restaurant? Whatever it was, think of how many people were there and how many noises presented in that room. What was going on at that time? Was there music playing? Can you hear the noise from the kitchen? Or were there a lot of conversation was going on at the same time? But somehow you were able to engage in a one-on-one conversation or a small group conversation, didn’t you? You were experiencing the cocktail party effect.
In 1953, Colin Cherry introduced the term of Cocktail Party Effect. The human ability to focus on auditory signals in a busy environment while filtering out the other background noise. The following video will show you an example of the cocktail party effect:
https://www.youtube.com/watch?v=mN–nV61gDo
After watching the video, now you realize that you experience this event a lot in your life. How does the human body respond the Cocktail Party Effect? I have provided an audio recording to make you feel the experience of cocktail party effect.
“Rangga yang kamu lakukan ke saya itu jahat.”
After listening to the audio above, let us imagine that you were in the audio recording. To understand what your friend is saying. First your brain needs to segregate the individual sound from the overlapping mixture of sounds entering your hearing system. Our ear has an ability to decompose the audio signal and it can be used to visualize the signal.
We are unable to coerce our environment to produce the desired sound, subsequently all the sound around us will propagate into our ears and will be converted into electrical signals. These signals will be processed in the brain, auditory cortex.
The task of the auditory system is not only analysing and filtering the sound signals but also derive the representation of the signals that allow the listener to focus and understand what is being said by the speaker.
Unfortunately, a study found out that children struggle to hear and understand speech when multiple people are talking at the same time. But how if your children were already experiencing this effect at the school? Failure to recognize speech in classroom can form important consequences for a child’s educational achievement and social development, isn’t it scary?
Studies found that elementary schools in Indonesia have an inferior acoustic design; it represented by a very high background noise level of the schools. In 2018, a study observed that noise level in one of the elementary school in West Jakarta is 76,4 dB(A). Meanwhile based on Keputusan Menteri Lingkungan Hidup Nomor 48 Tahun 1996, the recommended background noise level in the school area is 55 dB(A). The question is, “How this condition contributes to the cocktail party effect in school?”
Let’s do a role play, if you were a student in the picture above, you have to listen all of the sounds that are produced by:
- Speech is produced by the teacher
- Speech is produced by classmates who are talking during the class
- Noise is produced by interior machine (Projector, PC, HVAC system, etc.)
- Noise is produced by outdoor activities
Subsequently you have to hear the overlapping mixture of sounds that travels through the air. To understand what the teacher is saying you have to pay close attention to the teacher thus your brain can segregate and neglect the sounds produced by all other sources. We have to remember that children have more difficulty understanding speech in noise compared to the adults. On average, 5 – to – 7 year – old children require a 3 – 6 dB more favourable SNR relative to adults to achieve a comparable speech detection, word identification, or sentence recognition performance in a speech–shaped noise masker. So, the cocktail party effect, is it still fun?
References:
The Cocktail Party Problem. (n.d.). Retrieved from https://www.brainfacts.org/thinking-sensing-and-behaving/thinking-and-awareness/2013/the-cocktail-party-problem.
McKenna, B. (2017, December 1). Let the Cocktail Party Effect Guide your Design. Retrieved from https://medium.com/@bmckenna/let-the-cocktail-party-effect-guide-your-design-65fe72a6c2e1.
Mcdermott, Josh H. “The Cocktail Party Problem.” Current Biology, vol. 19, no. 22, 2009, doi:10.1016/j.cub.2009.09.005.
Too Young for the Cocktail Party? . (2019). Acoustics Today, 15(1).
Written by:
Zulfi Aulia Rachman
