Definition of vocal sac in English:

vocal sac

noun

Zoology
  • (in many male frogs) a loose fold of skin on each side of the mouth, which can be inflated to produce sound.

    • ‘In Rhinoderma darwinii, males retain the tadpoles in their vocal sacs until the young metamorphose.’
    • ‘This frog thumps its gular pouch against the soft soil where it lies and rapidly inflates its vocal sac.’
    • ‘Calling site was noted by counting males in calling posture (or with an inflated vocal sac) near each pool.’
    • ‘Sex was determined from the presence or absence of vocal sacs and thumb pads.’
    • ‘There are dads who incubate their babies in their mouths, their vocal sacs, and in pouches.’