Reviewing Firecracker revealed that loss of function of CN V3 (branch to the tensor tympani) can lead to hypoacusis to low-pitch sounds.
A web and forum search mentioned both hyperacusis and hypoacusis with injury to this nerve or muscle (tensor tympani), with the majority of sources suggesting hypoacusis.
If the main action of the tensor tympani is to tense the tympanic membrane (TM) in response to loud noises to properly transmit sound, how does loss of function result in loss of low frequency sounds?
Referencing equations from physics (vibrations and waves), I can postulate that the tensor tympani also contracts at low frequencies to increase the tension (T) of the TM to increase those frequencies (f) to within a normally audible range according to the fundamental frequency formula [1]:
Or I may be way off-pitch.
1 http://hyperphysics.phy-astr.gsu.edu/hbase/waves/string.html
A web and forum search mentioned both hyperacusis and hypoacusis with injury to this nerve or muscle (tensor tympani), with the majority of sources suggesting hypoacusis.
If the main action of the tensor tympani is to tense the tympanic membrane (TM) in response to loud noises to properly transmit sound, how does loss of function result in loss of low frequency sounds?
Referencing equations from physics (vibrations and waves), I can postulate that the tensor tympani also contracts at low frequencies to increase the tension (T) of the TM to increase those frequencies (f) to within a normally audible range according to the fundamental frequency formula [1]:
Or I may be way off-pitch.
1 http://hyperphysics.phy-astr.gsu.edu/hbase/waves/string.html