Washington: Will you believe that a beautiful cocktail party complete with soft music and animated murmur is not good for a depressed person?

A depressed individual, brought to this cocktail party by a well-meaning friend, can slide further into himself, his inability to hear and communicate compounding his sense of isolation, warns a new study.

‘A lot of research has suggested that these people with elevated depression symptoms have a bias towards negative perception of information in this kind of environment,’ said Zilong Xie from University of Texas at Austin.

When a listener has difficulty understanding someone else's speech, the source of disruption can be placed into one of two categories -- energetic masking or informational masking.

In energetic masking, sounds from peripheral sources such as construction sites or passing airplanes interfere with speech perception.

In informational masking, the interference comes from linguistic and cognitive sources, such as the background din of human conversation.

Informational masking tends to place greater stress on executive function than does energetic masking, thereby turning a cocktail party, or a lecture hall, into a potentially isolating experience.

Psychoacoustics identifies five basic types of emotional speech - angry, fearful, happy, sad and neutral.

‘If we want to fully understand what is going on with speech perception, particularly in a multi-tonal condition, which very often happens in our daily lives, we need to look at those kinds of emotional speech,’ Xie said.

From previous studies, Xie and his colleagues predicted that the bias of people with elevated signs of depression towards remembering sad information might lead them to more easily detect negative information in these environments.

‘We found that people with elevated depression symptoms are generally poorer at hearing all types of emotional speech relative to people with low depression symptoms,’ Xie said.

The study was presented at the 169th meeting of the Acoustical Society of America (ASA) held recently in Pittsburgh.