why is speech audiometry important
PTA doesn't reflect the degree of handicap in speech communication
how does an SLP use speech audiometry
as a basis for therapy planning and counseling
what are the factors in speech audiometry
test environment, test procedures, test equipment, patient, clinician
sound field
when the output comes from loudspeakers its as if the client is "sitting in a field of sound
what is speech audiometry equation
20 dB SPL = 0 dB HL
if audiometer dial is set to 0
the stimulus delivered is actually 20dB SPL
how does MLV work
monitored live voice is where the clinician must monitor on the VU meter the level of her voice so that the input = the output.
what does the VU meter do
it indicates the volume of intensity of input
if the VU meter is standing at 0 then
the level of the attenuator is true output
if VU is not at 0
then we need to either add or subtract that amount of dB to the attenuator to show the true output
why need two room suite for MLV
because the client can hear the examiners voice directly instead of through the microphone with the measured dB
what is the advantage of a patient speaking the response
faster, rapport maintained between client and examiner
what is the disadvantage of a patient speaking the response
patient may have poor or unitelligible speech
why use or not use written response
advantage: patient's speech may be poor, perm. record
disadvantage: slow, takes time to score so rarely used
SDT
speech detection threshold: Lowest level in dB that can just detect presence of speech and identify it as speech 50% of the time
SAT
speech awareness threshold commonly used synonym for SDT
cold running speech
no particular meaning or interest; continuous without breaks, monotonous
SRT
Speech Recognition Threshold: lowest level in dB that can identify correctly the speech stimuli 50% of the time
speech reception threshold
earlier name for SRT
Hudgins
1947; came up with list of 84 words to use for SRT
criteria for words for SRT
1. familiarity 2. phonetic dissimilarity 3. normal sampling of English words 4. homogeneity with respect to audibility
Hersch
1952 refined the list of words to 36 words; 2 lists of 18 words
spondaic or spondee words
two-syllable words spoken with equal stress on each syllable and are easy to understand at faint hearing levels
examples of spondee words
airplane, toothbrush, hotdog, sidewalk, baseball, pancake, cowboy, armchair, eardrum
carrier phrase
say the word" not necessary but allows clinician to monitor voice on VU meter and make changes before saying spondee word if necessary
SRT testing procedures
similar to pure tone testing
down 10dB up 5 dB
Martin and Dowdy
1986 established the testing procedure for SRT
why use Martin and Dowdy's procedure
it requires no knowledge of other test results
similar to pure tone testing using the 5dB steps
what is SRT results used for
as a basis for setting a level for Word Recognition (WRS) testing; as a check on pure tone results; to categorize hearing loss; to help with judgements as to need for amplification; in hearing aid evaluations
what is the cross check equation
SRT = PTA +/- 5dB