WHAT IS A DAILY LISTENING CHECK (DLC)?
-A DLC is when the clinician checks all the audiological equipment before testing a patient.
-Should be performed on all patients
Purpose of Daily Listen Checks?
â€¢ Save time
â€¢ If there is problem with the equipment, we would like to fix it or find a solution BEFORE the patient is seen
â€¢ Ensure that test results obtained are accurate
â€¢ Is the person not responding because they have a HL or is it
because our equipment isn't functioning?
â€¢ RED FLAGS: Asymmetrical HL, No response in soundbooth but patient can hear just fine in person.
How do we run a daily listening check?
-You will need a partner to be in the sound booth. --First check, air conduction testing while using the headphones.
-The person in the booth should be able to hear the signal at each frequency (250-8000 Hz).
-Next, use the bone oscillator and to the same.
-Finally check sound field speakers.
-There is a checklist in the booths
Device that measures the immittance of the middle ear system, or how well the middle ear is functioning.
A Tympanometer includes...
â€¢ Acoustic Reflexes
â€¢ Acoustic Reflex Decay
â€¢ Eustachian Tube Function
Basic parts of a Tympanometer
â€¢ Immittance Bridge or the "Box" - holds the probe and stimulus tubes
â€¢ Probe tips - placed on the end of the probe, come in different sizes (adult - pediatric)
How do we run a daily listening check on a tympanometer?
â€¢ 1. You can check your own ear and should see normal
â€¢ 2. Use a 2 cc. Coupler that is in the clinic. You should see a volume of 2ml.
Otoacoustic Emmission (OAEs)
Device that tests the outer hair cell function of a person. You put a probe that plays an sound into each ear.
â€¢ Can be software installed on a computer
â€¢ Can be a handheld screener
How do we run a daily listening check on a OAEs?
Check BOTH ears!
â€¢ Make sure you can hear sounds playing out of each ear.
â€¢ If you have normal hearing you should have present OAEs
Daily listen checks for hearing screenings
always perform a listening check on the screening audiometer before taking it out of the clinic
â€¢International Organization for Standardization (ISO)
â€¢International Electrotechnical Commission (IEC): showing electronically it won't hurt anyone
â€¢American National Standard Specification for Audiometers (ANSI): depending on the class of audiometers they are putting out the same thing
â€¢Acoustical Society of America (ASA)
â€¢ASHA: require that if we take out a portable audiometer we fill out checklist and it needs to be completed before you screen (ANSI and licensure board require the same)
â€¢Texas Requirements: fill out green cards
â€¢On the General Audiometer Checklist (Ideally all should be checked "no" but #12 should be checked "yes.")
â€¢Required to check the Audiometers.
Parts of an audiometer
â€¢Attenuator- intensity dial
â€¢Frequency selector- lets you change the Hz you're testing
â€¢Talk over dial
â€¢Talk back dial
â€¢VU meter- for speech
Types of Transducers
â€¢Standard (regular headphones)
â€¢Inserts (makes sound louder so you have to adjust for that)
â€¢High freq. or Supra-aural headphones (whole ear is inside & lets us test 8K Hz)
â€¢Sound field (height, distance, and locations matter in terms of calibration)
â€¢Bone oscillator (calibrated on forehead or mastoid)
Has to be calibrated to each voice, use VU meter and strive for 0. Adjust while giving instructions
External inputs calibration
-Tape players, CDs, iPods, MP3s.
-Must be calibrated daily.
-Tones usually played at a 1000 Hz, but you need to adjust the tone at 0 on the VU meter.
VU meter calibration
-If you listen/use the microphone, it has to be calibrated through your voice. Strive to be right at 0.
-Works for your voice and external inputs
Types of Audiometers: 1-4
-1 is the best for diagnostics. Has all inputs
-4 is pure tones. NO speech, best for hearing screenings.
-Some may be able to turn up louder than they are calibrated for, so always check
Types of Audiometer: channels
-Internal components that let you
take a particular signal, specifically pure tone, control the frequency
and you can handle ears separately with 2 channels
-1 Channel: can only use one transducer at a time
-1 Â½ Channels: let's you do some things at the same time; just can't do two different transducers
-2 Channel: very expensive; handles ears complete separately
Types of Audiometers: A-C
-Type A: (the best) let's you do anything (i.e. microphone, CD) for speech testing.
-Type C: limited options (maybe a tape); least amount of speech ability
Calibration of audiometers
â€¢To ANSI standards
â€¢Annually â†’ most people hire a company to calibrate
â€¢Quarterly â†’only if we test in noisy environments, only for OSHA
â€¢Daily checks â†’ we do this if we are the 1st person in the clinic