Loss of auditory-nerve (AN) afferent cochlear innervation is a prevalent human condition that does not affect audiometric thresholds and therefore remains largely undetectable with standard clinical tests. AN loss is widely expected to cause hearing difficulties in noise, known as ‘hidden hearing loss’, but support for this hypothesis is controversial. Here, we used operant conditioning procedures to examine the perceptual impact of AN loss on behavioral tone-in-noise sensitivity in the budgerigar ( Melopsittacus undulatus; of either sex), an avian animal model with complex hearing abilities similar to humans. Bilateral kainic-acid infusions depressed compound AN responses by 40-70% without impacting otoacoustic emissions or behavioral tone sensitivity in quiet. Surprisingly, animals with AN damage showed normal thresholds for tone detection in noise (0.1 ±1.0 dB re. control animals; mean difference ±standard error), even under a challenging roving-level condition with random stimulus variation across tria...