Yenzheka has conducted various experiments and has successfully reproduced the purest and most authentic sound for attracting swiftlets, which are the main "ingredient" the whole birdnest farming ecosystem. All these sounds are packaged into CD/DVD format :

• Inner Sound - this is the sounds of baby swiftlets
• Outer Sound - this is the adult swiftlets' sound
• Roof Sound - this the sound generated by swiftlets when they gather