Read the passage given below and answer the question: Usually the first question I ask a newbie birder is, “What do you think is the most important physical requisite to be a birder? Your eyes, your ears, your nose or any other?”" Most often, the answer is “eyes”, but several do home into what is the most important faculty – at least, according to me: your ears. Spotting birds in foliage is hard enough, but if you hear them, you know they are there." But early the other morning, I realised it went much beyond that. The first bird call I heard as I left the house for my walk was the madcap ringing laugh of black-rumped flameback, earlier known as the golden-backed woodpecker. It was a wild, exultant laugh that set the tone and mood for the entire day. And then I realised that every bird call evokes a different reaction, memory or emotion in the listener." Indian mynas, for example, invariably remind me of people in Delhi – always ready to argue and pick a fight, belligerent and in your face. Yet, they taught me not to make sweeping generalisations because when a pair perch on the window sill in the afternoons, they have meaningful civilised conversations with each other. There is inquiry, humour and affection in their voices. 'It was a wild exultant laugh....' The underlined word is a/an_____.