This seminar is open to all NACS students.

Speaker: Anna Kraemer

Title: Auditory Threshold Sensitivity in the Developing Barn Owl

Abstract:

The barn owl (Tyto alba), an avian species that hunts prey at night, has highly accurate sound localization abilities (Payne 1971; Hausmann et al., 2008) and large hindbrain auditory nuclei (Kubke et al., 2004). Although most research has been focused on their sound localization abilities and the plasticity of this system (reviewed by Peña & DeBellow 2010; reviewed by Knudsen 2002), only a handful of studies have researched the development of a barn owl’s auditory sensitivity (Köppl and Nickel 2007). We have therefore used the auditory brainstem response (ABR) to assess the development of auditory sensitivity in barn owls   from posthatch day 4 (P4) to P65 and older by playing tone-burst stimuli over nine frequencies. The first auditory responses were recorded to 1 and 2 kHz at P4, followed by 0.5 kHz and 4 kHz at P8, and at P13, a consistent response was shown at 5 kHz. Sensitivity to increasing frequency increased with age, up to 12 kHz. Adult responses were recorded at P69. The results were compared with the cochlear action potentials made in developing barn owls in Köppl and Nickel (2007) and were similar at low frequencies, although ABR signals were detected earlier than CAP signals for stimuli above 5 kHz.