Recommendations for Audiometers for children age 3 and older
Minnesota Department of Human Services (DHS)
Minnesota Department of Health (MDH)
Child and Teen Checkups (C &TC)
C&TC strongly recommends a "puretone audiometric test using standardized testing methods" for the objective screen.
There are many different types of Puretone Audiometers on the market. MDH recommends the standard manual puretone audiometer, vs. automatic, as they allow for adjustments to the loudness, pitch and duration of the tone. The ability to adjust the loudness and duration is an important step in preparing the child for audiometry. These audiometers allow for manual presentation of a puretone at a specified loudness (i.e. 20 or 25 dB at a specific frequency, i.e. 500, 1000, 2000 or 4000 Hz). The American Speech, Language and Hearing Association (ASHA) recommended conditioning a child (under age 5 years) to the desired motor response prior to initiation of screening. This requires administering a minimum of 2 conditioning trials at a presumed suprathreshold to assure that the child understands the task. This can only be done on a manual audiometer (ASHA 2002).
Here is a partial list (in alphabetical order): Pictures are listed if a picture was available.
MANUAL PURETONE AUDIOMETERS
AMBCO puretone audiometer (puretone air conduction, very small and portable)
GSI 17 (puretone air conduction)
Beltone 119 (puretone air conduction)
Beltone Audio Scott (puretone air conduction)
Pictures below courtesy of Maico Diagnostics
MA27 (puretone air conduction)
MA25 (smallest Maico puretone air conduction audiometer
MA39 (puretone air conduction)
MA40 (puretone air conduction with bone)
MA41 (puretone air conduction with bone and speech)
MI26 (combination (puretone air conduction audiometer and tympanometer)
AUTOMATIC PURETONE AUDIOMETERS
(FYI only, not recommended for screening children under age 7 years old)
As indicated above, manual puretone audiometers allow for adjustments to the loudness, pitch and duration of the tone. These factors are needed for preparing the child to be successful in their attempt and also for play audiometry. Automatic puretone audiometers, (both the hand held type and the VASC type) do not allow for variation of these factors. Handheld devices are not recommended in the school-age population based on the high false positive rate (Bess, Dodd Murphy, & Parker submitted). Automatic puretone audiometers can be used on any population base, regardless of the language spoken.
Types of Automatic Puretone audiometers on the market.
MAICO Pilot Audiometer. (not recommended by MDH)
Picture courtesy of Maico Diagnostics
This is a puretone and speech-screening audiometer. This is a Verbal Auditory Screening for Children (VASC). Essentially, a child listens to a list of two-syllable words and then points to a corresponding picture, e.g., ice cream cone, fire truck, sailboat, bathtub, toothbrush, sandbox and others. The first word is presented at 50 dB (speech audiometry) and each successive word is presented at 4 dB softer. There are three words presented at 15dB at the end and the child must get two of the three correct to pass. MDH does not recommend it for objective screening because it:
- Misses high frequency hearing loss (in the 1000-4000 Hz )
- It is not culturally sensitive, only one language
- Inflexible as the child can guess and use the process of elimination as he or she goes through the test and get more correct responses than he or she could. The child needs to only hear part of a word to identify a named picture. You cannot adjust the decibels manually; the tones are presented automatically with a choice of 50dB down to 0 or 25 dB down to 0. It has been demonstrated that several types of hearing losses may not be detected using voice varieties of audiometers.
Welch Allyn Audioscope 3 Handheld audiometer (MDH does not recommend this for screening children under age 7 years
Picture courtesy of Welch Allyn
This automatic audiometer presents tones at the recommended frequencies (Hz) and intensities (dB). Once you depress the start button, there is no stopping the test until it is complete. It will automatically present the tones at the 4 frequencies.
The instrument has been validated as a screening tool for hearing loss for the elderly (Jama. 1988). This test is especially difficult for young children due to factors mentioned above.
In one study (J. Laryngol Otol, 1992), of 100 children (with the diagnosis of secretory otitis media) standard pure tone audiometry had a specificity (those who are truly negative) of 92 percent and sensitivity of 51.6% (those truly positive). The audioscope had a specificity of 84.2% and sensitivity of 57.5%. In another study (Orlando and Frank, 1987), Audioscope screening was feasible beginning at age 5 years if an over referral rate of about 56% (compared with about 18% for regular audiometric screening) can be tolerated.
Bess, F.H., Dodd Murphy, J., & Parker, R.A. (submitted). Children with minimal sensorineural hearing: Prevalence, educational performance, and functional status.
Guidelines for Audiologic Screening, American Speech and Hearing Association (ASHA) 2002 Desk Reference, Volume 4, p. 362.
Lichtenstein, M.J., Bess, F.H.., Logan, S.A., Validation of screening tools for identifying hearing-impaired elderly in primary care. JAMA 1988 (19) 2875-8.
Orlando, M.S., Frank T., (1987). Audiometer and Audioscope hearing screening compared with threshold test in young children. The Journal of Pediatrics (110) 2. 261-263.
Vaughan-Jones R, Mill, R.P (1992). The Welch Allyn audioscope and Microtymp: their accuracy and that of pneumatic otoscopy, tympanometry and pure tone audiometry as predictors of otitis media and effusion. J. Laryngol Otol. 106 (7):600-2.