TY  - CHAP
M1  - Book, Section
TI  - Audiology
A1  - Chan, Yvonne
A1  - Goddard, John C.
PY  - 2019
T2  - K.J. Lee’s Essential Otolaryngology: Head and Neck Surgery, 12e
AB  - Sound:  energy  waves  of  particle  displacement,  both  compression  (more  dense)  and  rarefaction  (less  dense)  within  an  elastic  medium;  triggers  sensation  of  hearing  by  vibrating  the  tympanic  membrane.Amplitude  of  sound:  extent  of  vibratory  movement  from  rest  to  farthest  point  from  rest  in  compression  and  rarefaction  phases  of  energy  waves.  In  psycho  acoustics,  sounds  with  higher  amplitudes  are  perceived  as  louder  than  sounds  with  lower  amplitude.Intensity  of  sound:  amount  of  sound  energy  through  an  area  per  time;  refers  to  sound  strength  or  magnitude.Sound  pressure:  sound  force  (related  to  acceleration)  over  a  surface  per  unit  time.Decibel  (dB):  unit  to  express  intensity  of  sound;  more  specifically  the  logarithm  of  the  ratio  of  two  sound  intensities.  One-tenth  of  a  Bel  (named  for  Alexander  Graham  Bell).Frequency:  number  of  cycles  (complete  oscillations)  of  a  vibrating  medium  per  unit  of  time;  psychoacoustic  correlate  is  pitch.  Time  for  completion  of  one  cycle  is  the  period.Hertz  (Hz):  in  acoustics,  unit  to  express  frequency  (formerly  cycles  per  second  or  cps).  Human  ear  capable  of  hearing  from  approximately  20  to  20,000  Hz.Pure  tone:  single-frequency  sound;  rarely  occurs  in  nature.Complex  sound:  sound  comprising  more  than  one  frequency.Noise:  aperiodic  complex  sound.  Types  of  noise  frequently  used  in  clinical  audiology  are  white  noise  (containing  all  frequencies  in  the  audible  spectrum  at  average  equal  amplitudes),  narrow  band  noise  (white  noise  with  frequencies  above  and  below  a  center  frequency  filtered  out  or  reduced),  and  speech  noise  (white  noise  with  frequencies  >  3000  and  <  300  Hz  reduced  by  a  filter).  However,  the  term  “noise”  can  also  mean  any  unwanted  sound.Resonant  frequency:  frequency  at  which  a  mass  vibrates  with  the  least  amount  of  external  force;  determined  by  elasticity,  mass,  and  frictional  characteristics  of  the  medium.  Natural  resonance  of  external  auditory  canal  is  approximately  3000  Hz;  of  middle  ear,  800  to  5000  Hz,  mostly  1000  to  2000  Hz;  of  tympanic  membrane,  800  to  1600  Hz;  of  ossicular  chain,  500  to  2000  Hz.  
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/19
UR  - accesssurgery.mhmedical.com/content.aspx?aid=1172368881
ER  -