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# Cocktail-party effect in king penguin colonies

## Details

**Authors** Aubin and Jouventin

**Year** 1998

**Publisher** Proceedings of the Royal Society Of London

**Discipline** Biology

[Read it at the publisher](https://doi.org/10.1098/rspb.1998.0486) 
10.1098/rspb.1998.0486

## In authors' words

### Abstract

The king penguin, Aptenodytes patagonicus, breeds without a nest in colonies of several thousands of birds. To be fed, the chick must recognize the parents in a particularly noisy environment using only vocal cues. The call an adult makes when seeking the chick is emitted at a high amplitude level. Nevertheless, it is transmitted in a colonial context involving the noise generated by the colony and the screening effect of the bodies, both factors reducing the signal–to–noise ratio. In addition, the adult call is masked by a background noise with similar amplitude and spectral and temporal characteristics, enhancing the difficulty for the chick in finding its parents. We calculate that the maximum distance from the caller at which its signal can be differentiated from the background noise (signal–to–noise ratio equal to 1) should not exceed 8–9 m in a feeding area. But our tests show that, in fact, chicks can discriminate between the parental call and calls from other adults at a greater distance, even when call intensity is well below that of the noise of simultaneous calls produced by other adults. This capacity to perceive and extract the call of the parent from the ambient noise and particularly from the calls of other adults, termed the ‘cocktail–party effect’ in speech intelligibility tests, enhances the chick's ability to find its parents.

### What they set out to do (purpose)

Do King Penguins experience the "cocktail party effect"?

### What they found (results)

Chicks clearly recognized their parents unique call, and notably the other chicks didn't react to non-parental calls.

## Commentary

### In short

Humans are not the only species who makes auditory distinctions, further supporting the case for the universality of the patterns.

### In more detail

The ability to make auditory distinctions has been examined in more than humans. Aubin and Jouventin 1998 researched the cocktail party effect within king penguin colonies. The ability to Distinguish parental calls from the calls of the other adult penguins is essential to a chick’s survival, as king penguins breed in colonies of several thousand individuals. There are many factors simultaneously happening as the parent birds call their chicks, including all the other parents calling for their chicks, the calls of other birds, and background noise. They hypothesized that the chicks would have to be within a distance of 8-9

meters to make the needed auditory distinctions, however, their results showed that a much greater distance of 11 meters was possible. They observed and measured approximately 40,000 pairs of adults and around 1,500 chicks and recorded and analyzed the frequency and sound pressure level of the adult penguin pairs. They followed and recorded the birds until they met up with their chick. They then tested the chick's response to those recordings and noted behavioral changes in the chick when it recognized its parent’s call. Usually, the chick “turned its head in the direction of the signal source, called in reply, and then approached (often running) directly towards the loudspeaker.” Notably, the other chicks in the vicinity did not react to the call. This research demonstrates that the ability to distinguish is not only a human one, but is also seen in other species of animals (including bees [10,11], etc.), and Distinction-making is often essential to the survival of the species.

**Patterns it shows** D

**How to cite this** Aubin and Jouventin (1998). Cocktail-party effect in king penguin colonies. Proceedings of the Royal Society Of London.