Trace airborne sound to an auditory nerve signal.	Pinna and canal -> eardrum -> malleus, incus, stapes -> oval window/cochlear fluid -> hair-cell transduction -> auditory nerve signaling.
What do the cochlear base and apex favor?	The base favors higher frequencies; the apex favors lower frequencies. Bending hair-cell stereocilia initiates mechanotransduction.
What does an AC threshold assess?	Air conduction uses outer/middle-ear transmission plus cochlear and neural detection. AC alone does not locate a loss.
What does BC bypass, and what must still work?	It bypasses outer/middle-ear transmission. Cochlear transduction and auditory neural pathways are still needed.
Why may unmasked BC fail to identify the responding ear?	Skull vibration can reach both cochleae. The more sensitive cochlea may respond regardless of vibrator side; masking may be needed.
Does a positive Rinne result prove normal hearing?	No. AC perceived longer/better than BC occurs in normal hearing and in sensorineural loss.
What can a negative Rinne result suggest, and what is a trap?	It may suggest a conductive component. Profound unilateral sensorineural loss can cause a false negative through the other cochlea.
How does a simple unilateral loss affect Weber?	Conductive loss tends toward the affected ear; sensorineural loss tends toward the better ear. Mixed/asymmetric cases need more evidence.
Does a midline Weber response rule out impairment?	No. It can occur in normal hearing or symmetric hearing loss.
How do audiogram axes work?	Hz increases logarithmically left to right; dB HL increases downward. One octave horizontally equals 20 dB vertically. Zero dB HL is not silence.
Name the AC symbols used in the guide.	Unmasked: right O/red, left X/blue. Masked: right triangle/red, left square/blue. Check the actual chart legend.
Name the conventional mastoid BC symbols.	Unmasked right <, left >; masked right [, left ]. Unmasked symbols locate the vibrator, not necessarily the responding cochlea.
How is an air-bone gap calculated?	AC minus BC at the same frequency, using reliable ear-specific results when required. Gap size is not overall severity.
How do conductive, sensorineural and mixed patterns differ?	Conductive: normal-range BC, poorer AC and gap. Sensorineural: both poorer without significant gap. Mixed: poorer BC plus an additional AC gap.
What can a three-frequency PTA hide?	Averages at 500, 1000 and 2000 Hz can hide substantial loss at 4000 or 8000 Hz. Report the individual-frequency pattern too.
How do hearing aids and cochlear implants differ?	Aids amplify sound for surviving cochlear/neural function. Implants bypass damaged hair cells and stimulate auditory nerve fibers. Neither restores normal hearing; professional assessment and individual preferences guide options.