Speech Audiometry: The Basics, Masking, & Advanced Speech Tests

Ozarks Technical Community College

Different Types of Speech Tests

Threshold tests Supra-threshold tests Speech-in-noise tests

The Staples

Speech reception threshold (SRT) This may also be called speech

recognition threshold Word recognition score (WRS)

This may also be called speech discrimination score

Special Considerations

If the patient is not a native English speaker, you may need to skip speech audiometry and note why you didn’t perform speech testing on the audiogram.

If you have hearing loss (as the tester) you may have difficulty hearing what the patient said. Don’t be afraid to ask the patient for clarification on

a word or to use the word in a sentence if you aren’t sure what they said.

Have the patient face you so you can read their lips (just make sure they can’t see your lips if you aren’t using a recorded list)

Threshold Tests

SRT

Speech reception threshold (SRT) The softest level (dB HL) at which a patient can

accurately repeat spondees (two-syllable words; i.e. baseball, hotdog, birthday) 50% of the time

SRT is primarily used as a reliability check▪ In comparing the SRT to the PTA, they should be

within 10 dB of each other▪ The patient should be able to repeat words about as softly as

they can hear tones at .5, 1, and 2 kHz

▪ If you have poor SRT-PTA agreement, then the reliability of your results should be considered to be questionable

SRT procedure

Same procedure as determining thresholds for tones Tell the patient: “You will hear some soft two-syllable words.

Please repeat the words as best as you can. If you’re not sure of a word, please try to take a guess.”

Start at the patient’s most comfortable level Use the same bracketing technique as puretone

testing If they repeat word correctly, decrease intensity by 10 dB If they miss the word, increase intensity by 5 dB

SRT is the softest level at which the patient accurately repeats spondees 50% of the time with at least 3 correct responses at that intensity

Masking for SRT

Just like masking for puretones Determine the need for masking and use plateau method to determine

effectively masked threshold for speech

Consider the interaural attenuation (IA): 40 dB for headphones 70 dB for inserts 0 dB for bone (you probably won’t do a bone-conducted speech test,

though it is possible and very useful in children)

The same rules apply for speech Take your SRT in the TE minus the best bone conduction threshold in the

NTE. If that value is greater than the IA, you need to mask.▪ Example, if your SRT using traditional headphones is 50 dB in the TE and the best

BC threshold in the NTE is 5 dB (50dB-5dB=45 dB), you need to mask since 45 dB is greater than 40 dB.

▪ ***Note: usually you have not yet performed BC when you are performing SRT, so assume air=bone. Alternatively, you can subtract the SRT of the NTE from the SRT of the TE to determine the need for masking. Just keep in mind that the SRT is an air-conduction test and you mask based on the BC scores of the non-test ear.

Masking for SRT

How much noise? If you’ve determined the need for masking, add

10 dB to the SRT of the non-test ear and present a spondee at threshold

Just like puretone masking utilizing the plateau method, if they get the word correct, then increase masking by 5 dB and present another spondee and repeat until your 15 dB masking plateau is achieved. Or, if they cannot repeat the spondee, increase the presentation level in 5dB steps until threshold is reached and plateau your masking level accordingly.

An Important Note on SRT

Do NOT waste too much time on SRT As far as clinical utility is concerned,

SRT is low on the priority list Puretone thresholds and WRS are

much more important Get it and go

SAT

If a patient is unable to repeat spondees for any reason (i.e. poor speech discrimination, non-verbal, non-English speaking), a speech awareness threshold (SAT) or speech detection threshold (SDT) can be obtained. This is the softest level that the patient can hear

or detect speech Task=push the button when you are aware that

speech is present Usually, the SAT is equal to the patient’s best

puretone threshold on the audiogram in the TE

Supra-Threshold Tests

WRS

Word recognition score (WRS) The percentage of phonetically-balanced, monosyllabic

words that a patient can accurately repeat Presented at either MCL (most comfortable level) or MIL

(most intelligible level)▪ This is generally thought to be approximately 30-40 dB SL re:

SRT A pre-recorded list of 25 to 50 words should be

presented to each ear▪ Most common word lists: CID W-22 and NU-6

Each word should be preceded by a carrier phrase:▪ “Say the word pick”▪ “Say the word room”

WRS

When scoring a patient’s performance on WR testing, you must remember that wrong is wrong! The patient should only be given one

attempt at each word (oftentimes if they miss a word the first time, they will ask you to repeat it…don’t)

Close isn’t correct▪ i.e. If they say the word “eats” for “eat”

WRS in determining site-of-lesion

Patient’s with normal hearing or conductive hearing loss will perform normally on WR testing

Patient’s with only high-frequency or a mild, flat SNHL will also generally perform near-normal

The more severe the SNHL, the poorer a patient will perform on WR testing

Neural losses result in poor performance

WRS in determining site-of-lesion

Asymmetrical WRS, especially in the presence of puretone asymmetries, should be considered a “red flag” for an acoustic neuroma

In patient’s with a retrocochlear lesion, roll-over may also be present on WR testing. This means that with increased presentation level, the patient’s performance will actually decrease (i.e. 56% at 85 dB decreasing to 12% at 95 dB).

Recorded vs. MLV

Ideally, recorded word lists should be used when performing speech audiometry Limits variability from test-to-test

If the clinician says the words while monitoring his/her voice to make sure they are peaking their voice at 0 on the VU meter, this is called a monitored-live voice (MLV) presentation method.

Masking for WRS You will be much more likely to mask for WRS than SRT since

WRS is a supra-threshold test

Consider the interaural attenuation (IA): 40 dB for headphones 70 dB for inserts 0 dB for bone (you probably won’t do a bone-conducted speech test,

though it is possible and very useful in children)

The same rules apply for speech Take your presentation level in the TE minus the best bone

conduction threshold in the NTE. If that value is greater that the IA, you need to mask.▪ Example, you are performing WR testing using traditional headphones at 75

dB in the TE and the best BC threshold in the NTE is 20 dB (75dB-20dB=55 dB). So, you know you need to mask since 55 dB is greater than 40 dB.

▪ ***Note: usually you have not yet performed BC when you are performing WRS, so assume air=bone. Alternatively, you can subtract the SRT of the NTE from the presentation level to determine the need for masking, but, again, the SRT is an air-conduction test.

Masking for WRS

How much noise? If you’ve determined the need for

masking, add 10 dB to the SRT of the non-test ear + an extra 15 dB for your plateau. So…

Noise in NTE = SRT of NTE + 25 dB▪ Ex: The SRT of the NTE is 30 dB, so you add

25 dB to arrive at your masking level of 55 dB in the NTE.

Speech-in-noise Tests

QuickSIN & ANL

Both tests measure a patient’s ability to understand speech in the presence of background noise (#1 complaint of hearing-impaired)

Useful in making treatment recommendations and in counseling re: realistic expectations

See supplemental materials re: QuickSIN and ANL