Hosts Phil Thompson and Eric Armstrong work their way across the Pulmonic Consonant Chart, focusing in on the Fricative row. Though they do cover English fricatives [θ ð f v s z ʃ ʒ], they go into much greater depth on the non-English sounds [ɸ β ʂ ʐ ç ʝ x ɣ χ ʁ ħ ʕ ʜ ʢ h ɦ ]. (note that they follow the IPA chart on the wikipedia page, which sort of blends the very back fricatives with the approximants.)