Swiftlet Sound

A very effective external swiftlet music / sound that attract swiftlets and encourage them to stay and nest.Since birdnests farmers started to use audio system to attract swiftlets into their birdhouses, many varieties of swiftlet sound have been created. Nowadays, the two main ones are the external and internal sound.The external sound, as the name implies, are to be used at the exterior of a birdhouse. It is a mixture of adult birds and baby.