In 1969, Irv Teibel began releasing a series of digitally processed field recordings meant for use as work, sleep and relaxation aides. These 11 albums form the environments series (title stylized in lowercase.) 17 of the 22 pieces were made available on cassette as part of a 1987 reissue campaign of 16 cassettes, one piece per cassette (except for cassette 14); environments 1 through 3 would be reissued that same year on CD in entirely new and exclusive remixes. All 11 albums were eventually remastered and reissued by Numero Group in 2018 as an app for iOS and Android.