Audiometric Testing Procedures Flashcards

During pure-tone air conduction audiometry, what is the standard procedure for finding the threshold of hearing after a patient responds to a tone?

Answer: Decrease the intensity by 10 dB and present the tone again.

The modified Hughson-Westlake method, a standard procedure for threshold search audiometry, involves decreasing the intensity by 10 dB after a patient response ('down 10') and increasing it by 5 dB after a non-response ('up 5'). This bracketing technique helps to accurately pinpoint the softest level a person can hear approximately 50% of the time.

A client's unmasked air conduction threshold in the right ear at 2000 Hz is 50 dB HL. The bone conduction threshold in the left ear (non-test ear) at the same frequency is 10 dB HL. Using supra-aural headphones with an interaural attenuation of 40 dB, is masking required for the right ear, and why?

Answer: Yes, because the difference between the air-conduction threshold in the test ear and the bone-conduction threshold in the non-test ear is greater than the interaural attenuation.

Masking is needed to prevent the non-test ear from responding to the signal (cross-hearing). The rule is to mask when the air conduction threshold of the test ear (ACte) minus the interaural attenuation (IA) is greater than or equal to the bone conduction threshold of the non-test ear (BCnte). In this case: 50 dB (ACte) - 40 dB (IA) = 10 dB. Since 10 dB is equal to the BCnte (10 dB), there is a risk of cross-hearing, and masking is required.

Which of the following best describes the primary purpose of bone conduction audiometry?

Answer: To assess the sensitivity of the sensorineural system by bypassing the outer and middle ear.

Bone conduction testing transmits sound vibrations directly to the inner ear (cochlea), bypassing the outer and middle ear. This allows the audiologist to determine if a hearing loss is conductive (problem in the outer/middle ear), sensorineural (problem in the inner ear/auditory nerve), or mixed.

A patient is unable to repeat spondee words to establish a Speech Recognition Threshold (SRT). Which test would be the most appropriate alternative to obtain information about their threshold for speech?

Answer: Speech Detection Threshold (SDT) / Speech Awareness Threshold (SAT)

The Speech Detection Threshold (SDT), also known as Speech Awareness Threshold (SAT), is the lowest level at which a patient can just detect the presence of speech 50% of the time, without needing to understand or repeat it. This makes it a suitable alternative when an SRT, which requires word repetition, cannot be obtained.

According to ASHA guidelines, what is the recommended starting frequency for pure-tone threshold testing?

Answer: 1000 Hz

Testing should begin at 1000 Hz because it is a frequency easily heard by most patients and has the highest test-retest reliability. After testing higher frequencies, it is common practice to retest 1000 Hz to ensure reliability before proceeding to lower frequencies.

During audiometric testing, you establish an air-bone gap of 20 dB in the right ear. What does this finding most likely indicate?

Answer: A conductive or mixed hearing loss in the right ear.

An air-bone gap occurs when bone conduction thresholds are better (lower) than air conduction thresholds by 15 dB or more. This indicates that sound is not being conducted efficiently through the outer or middle ear, pointing to a conductive component in the hearing loss. If the bone conduction is normal, it's a conductive loss; if the bone conduction also shows a loss, it's a mixed hearing loss.