Tdt auditory evoked potential workstation

The hearing level of each mouse was checked by measuring the auditory brainstem response (ABR) threshold with a TDT auditory evoked potential workstation (Tucker-Davis Technologies, Alachua, FL, USA) as described previously [10 (link)]. Mice were anesthetized by IP injection of ketamine hydrochloride (30 mg/kg) and xylazine (2 mg/kg). Both ears of each mouse were stimulated with an ear probe sealed in the ear canal. The ABRs to click and tone stimuli were recorded, and thresholds were obtained for each ear. ABRs were measured before noise exposure, immediately after noise exposure, 2 days after noise exposure, and 6 days after noise exposure.

White noise (300–10,000 Hz) was generated using a personal computer and an amplifier (R-399; Inter M, Seoul, South Korea) and delivered through speakers (290-8L; Altec Lansing, Oklahoma City, OK, United States) in a noise booth. Mice were continuously exposed to a 120-dB peak equivalent sound pressure level for 1 h to produce permanent threshold shift and acoustic overstimulation-induced cochlear inflammation.
The auditory brainstem response (ABR) was measured after anesthetizing the mice with xylazine [20 mg/kg, intraperitoneal injection (IP)] and ketamine hydrochloride (30 mg/kg IP). The hearing level of each mouse was checked by measuring the ABR threshold with a TDT auditory evoked potential workstation (Tucker-Davis Technologies, Alachua, FL, United States). Both ears of each mouse were stimulated with an ear probe sealed in the ear canal. The ABRs to click and tone burst stimuli were recorded, and thresholds were obtained for each ear. The ABRs were measured before and at 2 and 7 dpn.