Lesson 4 Flashcards
Task to measure hearing ability. Human has audible range. Not all range in this experiment. 30 to 16k
longtudin. wave. compressions in air - travel to ear. vacuum in room –> sound doesnt travel. Needs matter!
Transverse oscilates perpendi. to directon of wave
longt. eg spring
Curve in pres. describes hearing threshold. Lower part - freq. we hear better! Inverse graph!!
unit db in logaritmic scale - use becaiuse huge difference between hearing and pain threshold. 12 zeros for 120 db!
sound into ear canal. shakes eardrum with airprusserese, transfered to 3 bones. sound from eardrum to oval window. 55m2 to 3 mm2. Area smaller - higher pressure. Conclude that the 3 bones are boosting the sound. Losing one of 3 bones or eardrums - people hear things 1000 times quieter than normally.
cochlea different freq. spiral from higjest to lowest.
questions about hearing loss!!!
Comparing our curves to theoretical curbes in present. !!
Caiuse: bad headphones? Something abt the ear.
Compare ear between themselves!
no one will have same 0 value –> relative!
2st 50 db speakers –> only 3db boost
we hear this freq. region of human voice. made for listening to other bozos.
appl. in medic.
Asculatation performed with a stethoscope. Listen to pusle, heart
Percussion, knock on surface to determine the structure! Difference between concrete etc
clinical audiomery: test peoiples hearing
Phonocardiography: listen to heart valves
Tasks
Kan komma fråga om att nämna systematic errors!!!
Should we unhand in the oscilations lab work and write concl. etc in the right place
