( CNN ) -- You know the voice of Morgan Freeman : commanding , firm , resonant . He 's even played God . What if it 's on helium ? Call it `` undignified . '' Freeman did . On Thursday 's `` Tonight Show Starring Jimmy Fallon , '' the Oscar-winning actor reluctantly agreed to conduct an interview with host Fallon after inhaling from a helium-filled balloon . It was a recreation of a bit from his Emmy-nominated Science Channel show , `` Through the Wormhole with Morgan Freeman . '' `` I really should n't be doing this , '' said Freeman squeakily , glaring at Fallon as the two took hits from the balloons . `` It 's very undignified . '' As Fallon fell about laughing , he asked if Freeman would return . `` I 'm never coming back , '' replied the actor , after inhaling again . Perhaps Fallon can persuade James Earl Jones to substitute . Freeman appears in the thriller `` Lucy , '' starring Scarlett Johansson , which opens Friday . Review : 'Lucy ' has no boundaries . Chris Christie , Jimmy Fallon dance around testy issues .
Morgan Freeman goes high-pitched on Fallon 's show . Comment: Freeman gamely went along with idea .