Most acute hearing for a lizard

The lizard with the most acute hearing is the peace delma Delma pax, a species of pygopod or Australian legless gecko. It can detect and respond to a 60-decibel sound with an 11.1 kHz frequency. This is more than an octave above the highest note on a standard piano. They are commonly termed legless lizards, and while they do lack forelimbs the pygopods still possess vestigial hindlimbs, which take the form of small flattened flaps. The function (if any) of these flaps is unclear – some researchers believe that they may aid in courtship, while others have suggested a role in defence or even in locomotion through vegetation.