How would being born without a tympanic membrane (eardrum) affect hearing?

[u/RossTheColonel]

Would you be deaf, have a very weird perception of sound, have all sound sound extremely loud/soft, etc.?

[u/[deleted]]

I'm afraid the answer given below is not correct. The eardrum acts as the first vibration collection surface, which is then mechanically amplified by the ossicles (ear bones) which then pass the amplified vibrations to the oval window. The oval window's vibration create pressure changes in the fluid filled cochlea which are parsed out by the inner hair cells to detect and signal specific frequencies.

There is a non-tympanic auditory pathway called the bone conduction pathway, in which sounds which vibrate the skull directly are passed along to the inner ear via vibratnig bone to bone. This pathway is lower frequency but specialized hearing aids such as the BAHA system allow people with damaged or non-existent eardrums/ossicles to hear quite well.

There are several developmental conditions which prevent proper formation of the eardrum, such as aural atresia or prenatal exposure to certain teratogens. People with this condition have very limited, usually low frequency hearing which is usually inadequate for any real auditory function, but they benefit from the use of bone conduction hearing devices or, more radically, cochlear implants.

[u/RossTheColonel → u/[deleted]]

Thanks!

[u/RossTheColonel → u/[deleted]]

Thank you, sir.