You may download mp3 files of the pitches one at a time, or buy the whole album. If you have Apple Music, search ‘”Cello Drones for Tuning and Improvisation by Marcia Sloane” and you can stream this album for free.

https://smile.amazon.com/Drones-Improvisation-Musicians-Practice-Partner/dp/B001OS6R0Y/ref=smi_www_rco2_go_smi_g8217842112?_encoding=UTF8&%2AVersion%2A=1&%2Aentries%2A=0&ie=UTF8