It was this drum, which was sending the sounds whenever the branches of the tree above brushed against it. 
ɪt wɑz ðɪs dɹʌm, wɪtʃ wɑz sɛndɪŋ ðʌ saʊndz wɛnɛvɜ˞ ðʌ bɹæntʃʌz ʌv ðʌ tɹi ʌbʌv bɹʌʃt ʌɡɛnst ɪt. 
 Indian speaks with a very monotone tone in a recording where the sound is very clear and close to the microphone.