That includes first of all the "source" - the vocal folds that humans and many animals share.

BBC: Helium-huffing gibbons 'sing with soprano technique'

Denon has increased the number of HDMI inputs in its Retail Home Theater Series receivers (3 in the AVR-590, 4 in the AVR-790, and 5 in the AVR-890 and AVR-990), and now includes dual source and zone capabilities on all models with the exception of the AVR-590.

ENGADGET: Denon outs 2009 line of Blu-ray players, AV receivers and headphones