There is a constant artifact tone at 27233Hz on the original , this is ultrasonic so inaudible, but becomes audible when you slow it down and the pitch drops. A fair fraction of the slower versions is this whistle artifact, which was generated by the apparatus not by the crickets.
Thank you soo much for sharing this sound, I´m gonna use it in a children e-book namned; Bubba (iTunes) . The sound is soo funny and I´m sure the children gonna love it!! I´ve credit you in the e-book <3 <3