A honk is the sound a goose makes, or a noise that sounds like a goose. Car horns are often described as going "honk".
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A hum is a continuous, low sound, like the background noise running machinery makes. You can hum yourself, by singing with your mouth closed.
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People laugh as a reaction to something funny, or when they are tickled. Laughing is normally something you do when you are very happy.
A neigh is the noise a horse makes. Horses also snort and whinny, which is a similar noise to a neigh.
