Ian is never seen speaking, and his voice is only heard during his song Do You Love Me? where he speaks a seemingly gibberish language where the only known lyric is "Do You Love Me?" which is constantly repeated. He also speaks english, briefly, and claims to have 'Pain au Chocolat Tears'. It seems to be directed towards a piece of toast called Zissou which only says "Non" during the song. At the end of the song his head explodes, revealing a metal ball. However, in the tennis sketch later in the episode he has his head again. This shows that the ball was just effects, he always wears a 'mask' or it's just an editorial mistake.
In Episode 5 he is first with a waiter and Zissou performing a song presumabley called Do You Love Me? which is sung in a gibberish language. He also speaks english during the song. Using his 'Pain au Chocolat Tears' he creates a picture of Zissou. At the end of the song his head explodes, revealing a metal ball.
Later in the episode, he is seen playing tennis with Raymond Boombox with Secret Peter umpiring. He has his normal face back in this sketch. He is shown to be blatantly better that Boombox, who either hits the ball out or doesn't even bother abiding by the rules.