Frequency testing

• Frequency testing

• Uses intensity testing over frequency range.
• Loss of frequency level due to over stimulation that kills inner row hair cells.

• Intensity coding shown by monotone stimulation

• Hearing threshold Test
• Behavioral (just audible sound= 1 decibel)
• Auditory Brainstem Response (ABR)
• Louder sounds:
• Recruit more primary afferent fiber activation by receptor cells responding to a narrow frequency range.
• Faster firing rates of the 8th nerve afferents is due to more transmitter release.
• Too loud- middle ear muscle co-contraction response protects delicate inner ear structure above 100 dB.