Evoked Potential

University of the Pacific Audiometric Evaluation

  • Obtain Case History - See Form
  • Otoscopy
  • Immittance Measurements
  • Audiometry
  • OAEs after Audiometry
  • Counseling
  • Report/Chart Notes
Immittance Measurements
Audiometry
As a general rule, start with the better hearing ear, if the ears are the same, start with the right ear
SRTs/SDTs
  • Familiarize with spondee word list using MLV (monitored live voice)
    • start presentation at 65 db HL in binaural condition
      • confirm with patient if the volume is comfortable
      • use at least 9 - 12 words to familiarize
  • Use the bracketing method
  • Threshold is defined as the lowest level at which 3 words are correctly repeated
  • Spondee list of 15 of the most homogenous words
    • ​baseball, doormat, drawbridge, eardrum, grandson, inkwell, mousetrap, northwest, padlock, playground, railroad, sidewalk, toothbrush, woodwork, workshop 
MCL
  • Use MLV​ (monitored live voice); give running speech
  • Use bracketing procedure, even if the patient says the first presentation volume is comfortable
UCL
  • Test using MLV (monitored live voice)
  • Instruct at MCL and then increase in 5dB steps until "uncomfortably loud
Air Conduction Pure Tone Thresholds
  • Use insert earphones, unless contraindicated and a pulsed or warble tone
  • Start at 1kHz
    • ​begin presentation at obtained MCL for familiarization and then begin threshold searches
  • ​​​Use Hughson & Westlake bracketing method
  • Threshold Test order: 1k, 500, 250, 2k, 3k, 4k, 6k & 8k
    • ​Include other inter-octaves if there is a difference of 20dB or more between thresholds
  • ​Threshold is determined to be the level where 2 out of 3 correct responses are obtained at the lowest ascending test level
  • Mask as needed
  • ​​Compare calculated PTA to the obtained SRTs to determine test reliability
  • Mask as needed
    • ​Masking criteria
      • ​Air Bone Gap is > 40 dB (headphones)
      • Air Bone Gap is > 50 dB (insert earphones)
      • Applies to SRT and Pure Tones
Word Recognition
  • Use an NU-6 word list
  • If a patient scores 9/10, score 96% (Thornton & Raffin)
  • For all other scores, score normally and note how many words are tested in the report
  • Test presentation criteria (based on Guthrie & Mackersie recommendations)
  • If word rec scores are significantly different between ears or different from a previous test, consider re-testing at +10dB HL to see if the score improves
    • ​Report on the significance of difference between ears/previous test (using Thornton & Raffin criteria)
QuickSIN
  • Test binaurally, unless there is a significant hearing loss asymmetry between ears
  • Test presentation criteria:
    • For PTAs </= 45 dB HL = test at 70 dB HL
    • For PTAs > 45 dB HL = test at UCL - 10
  • Perform a total of 3 lists; do not score the first practice list
Bone Conduction
  • Using a mastoid placement with ears un-occluded, obtain bone-conduction thresholds with the bone oscillator first on the right mastoid and then repeat on the left mastoid
  • Use threshold search method as described above for air conduction thresholds
    • important to test below 0dB
  • Mask as needed
    • ​Masking Criteria - Mask if Air Bone Gap is > 10 dB so if there is a 15 dB gap
OAEs

Capella System
  • Conduct on all patients except for patients who have documented no OAEs
  • Run Comprehensive protocol (currently compares to 95%tile Boys Town Research)
  • Remove and replace probe with each run

GSI System
  • Run the 1.5kHz - 8kHz protocol
  • Run DPOAEs for two runs in each ear
  • Remove and replace probe in between each run
Evoked Potential
1640 Stockton Street ​#330071
San Francisco, California 94133
hello@evokedpotential.com