Test procedure Several different methods followed. Several different methods followed. Most standard: Recommended by Carhart and Jerger (1959) and ASHA (1978) Most standard: Recommended by Carhart and Jerger (1959) and ASHA (1978) 1. Start at 1000 Hz, 30 dB HL. 2. If no response, raise to 50 dB HL, and continue to raise in 10 dB steps till response is obtained. 3. When response is elicited, then level lowered in 10 dB steps till no response is elicited. 4. Now, increase level in 5 dB steps till response occurs. 5. Then, lower in 10 dB steps. (Down 10, up 5) 6. Threshold: Lowest level at which response is given for at least two out of three presentations (ANSI, 1986).

Procedure, cont’d. Record threshold on audiogram. Record threshold on audiogram. Take into account correction factors, if any. Take into account correction factors, if any. Measure thresholds at all frequencies. Measure thresholds at all frequencies. Reliability of thresholds checked using 1000 Hz. Reliability of thresholds checked using 1000 Hz. Check poorer/other ear. Check poorer/other ear.

Audiogram: Graph of hearing as a function of frequency.

Audiogram data Identification: Name, date of testing, examiner, equipment Identification: Name, date of testing, examiner, equipment Unmasked AC thresholds (ASHA 1990): Unmasked AC thresholds (ASHA 1990): Red  for right ear Red  for right ear Blue X for left ear Blue X for left ear Symbols connected with red and blue solid lines. Symbols connected with red and blue solid lines. Pure tone average (PTA): Average threshold levels at 500, 1000, and 2000 Hz. Pure tone average (PTA): Average threshold levels at 500, 1000, and 2000 Hz. Sometimes, two-frequency PTA used: Average of two lowest thresholds at 500, 1000, and 2000 Hz. Sometimes, two-frequency PTA used: Average of two lowest thresholds at 500, 1000, and 2000 Hz.

Draw the audiograms for the following sets of audiometric data Right ear Left ear AC BC AC BC-5*05*10*0*0*0*5*5*0* AC BC AC BC25*30*35*40*50*25*30*40*50*55*

Interpretation of AC thresholds: Degree of hearing loss PTA (dB HL) Degree of Hearing Loss -10 to 15 Normal hearing 16 to 25 Slight hearing loss 26 to 40 Mild hearing loss 41 to 55 Moderate hearing loss 56 to 70 Moderately-severe hearing loss 71 to 90 Severe hearing loss > 91 Profound hearing loss