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Pure Tone Threshold Audiometry
Please visit this website for more information about this instrument: Pure-Tone Threshold Audiometry.
Example of the audiogram in American Speech-Language-Hearing Association. (1990). Audiometric symbols [Guidelines].
Supplemental: Cerebral Palsy (CP)
Short Description of Instrument
Pure-tone threshold audiometry measures an individual's hearing sensitivity for calibrated pure tones. Three general methods are used: (a) manual audiometry, also referred to as conventional audiometry; (b) automatic audiometry, also known as BÉkÉsy audiometry; and (c) computerized audiometry. Pure-tone threshold audiometry is used for both diagnostic and monitoring purposes (American Speech- Hearing-Language Association, Working Group on Manual Pure-Tone Threshold Audiometry, 2005; American Speech-Hearing-Language Association, 1990; 1974).
Comments/Special Instructions
Results may be recorded in graphic or tabular form or both. Audiologists' already have audiogram forms that they use.

Pure tone thresholds (in decibel hearing level dBHL) showing degree, configuration, and type of hearing loss, if any.

Audiogram form. When the graphic form is used, the test frequencies shall be recorded on the abscissa, indicating frequency on a logarithmic scale, and hearing levels shall be recorded on the ordinate, using a linear scale to include the units of decibels. The aspect ratio of the audiogram is important for standardization. The correct aspect ratio is realized when a square is formed between any given octave pair on the abscissa and any 20 dB increment on the ordinate. For conventional audiometry, the vertical scale is to be designated hearing level in decibels; the horizontal scale is to be labeled frequency in hertz. By convention, frequency is recorded in ascending order from left to right, and hearing level is recorded in ascending order from top to bottom, ranging from a minimum value of -10 dB to the maximum output limits of the audiometer (usually 110 or 120 dB HL). It is advisable when reporting extended high-frequency audiometric results to use a separate graph that incorporates the appropriate decibel scale (HL vs. SPL) and frequency range measured.
Audiogram symbols. When the graphic form is used, the symbols presented in the Guidelines for Audiometric Symbols (American Speech-Hearing-Language Association, 1990; 1988; 1974) should be used.
Every audiogram, whether graphic or tabular, should include, as a minimum, the following information:
  • date and location of test
  • names of participant, audiologist, and, if applicable, referral source
  • professional credentials, license, or registration held by the audiologist, as required
  • description of test equipment used, including audiometer and transducers, and the audiometric test room
  • calibration information for equipment used
  • threshold values for each of the frequencies tested for each ear by air conduction and bone conduction
  • explanation of all symbols used
  • observations of physical conditions of the outer ear or other conditions that may have influenced the results and any steps taken to mitigate these conditions
  • observations of participant behavior, symptoms, or difficulties
  • assessment of test reliability
  • reason for the evaluation
  • description of alternate test methods or nonstandard test stimuli used, for example,
    • "threshold determined by descending presentations method"
    • "pulsed tone substituted"
    • "warbled tone substituted"

American Speech-Hearing-Language Association, Working Group on Manual Pure-Tone Threshold Audiometry. Guidelines for Manual Pure-Tone Threshold Audiometry 2005 [cited 2022 10 August]. Available from:
American Speech-Language-Hearing Association. Guidelines for manual pure-tone threshold audiometry: ASHA; 2005 [cited 2016 6 July]. Available from:
Guidelines for audiometric symbols. Committee on Audiologic Evaluation. American Speech-Language-Hearing Association. ASHA Supplement. 1990(2):25-30.
Guidelines for audiometric symbols. ASHA. 1988;30(12):39-42.
Guidelines for audiometric symbols. ASHA. 1974;16(5):260-264.
Hidecker MJ. Describing hearing in individuals with cerebral palsy. Dev Med Child Neurol. 2011;53(11):977-978.
Reid SM, Modak MB, Berkowitz RG, Reddihough DS. A population-based study and systematic review of hearing loss in children with cerebral palsy. Dev Med Child Neurol. 2011;53(11):1038-1045.


Document last updated August 2022