Speech Audiometry SPA 4302 Summer 2007

The Diagnostic Audiometer Equipped with Inputs for microphones, cassette tapes, or CDs Volume unit (VU) meters Circuit for masking noise or mixing noise with speech in the same ear Ability to test __________ or ______________ Intensity levels ranging from ____ to ____ dB HL Outputs for __________ amplifiers (to speakers) Talkback system to allow patient/clinician communication from different rooms/booths

The Patient’s Role in Speech Audiometry Pt must know and be able to respond to word in the language of the test. Responses: –________________________

The Clinician’s Role in Speech Audiometry Must be able to convey to pt their task, Keep face from pt’s view Understand pt responses

Speech-Threshold Testing Speech Detection Threshold: lowest level at which the listener can tell that something is there (when the signal happens to be speech). Also called the ________________________. Speech Recognition Threshold: lowest level at which the listener can actual identify what the speech stimulus is. Also called the _________________

SRT Stimuli: Spondees 2-syllable words with ________________ can be divided into two monosyllables e.g., hotdog, baseball, whitewash, mousetrap, birthday, eardrum...

Why spondees? because their intelligibility curves rise from near chance to _______ performance within a few decibels. (see curve 1 in figure 5.1) This provides a much more accurate threshold.

SRT Methods Descending Approach Start approx ___dB above expected threshold Drop in __ dB steps 5 words per level Stop when pt misses 5 out of last 6 words Threshold = start level – number correct + correction factor Adaptive Approach Like Pure Tone procedure down in 10 dB steps, up in 5 dB steps Up to __ words per level Threshold = lowest level at which pt correctly id’s at least 2 words (>50%).

Masking for SRT If SRT - IA > best BC Thresh NTE Put in at least: STARTING LEVEL=SRT TE –35 +ABG NTE But no more than: OVERMASK = EM NTE -IA> Best BC Thresh TE

Most Comfortable Loudness Level Instructions important: you can strongly influence how a person responds. "I am going to continue talking to you as I make my voice louder and softer. I will keep asking you to tell me whether my voice is too soft, too loud or comfortably loud." Do a number of sweeps in level. normally between ___ and ___ dB above SRT

Uncomfortable Loudness Level Begin at ___, raise level as you continue to talk. "I am now going to ask you to tell me how my voice sounds to you as I make it louder. Please tell me if the level is comfortable, a little loud, or uncomfortably loud.” Uncomfortable = loud enough so you would not want to listen to my voice for a long time.

Range of Comfortable Loudness (Or the Dynamic Range for Speech) = UCL – SRT Normally ___ dB or greater Unchanged in ____________ losses Can be much smaller in ____________ hearing loss

Word Recognition Testing ________ set-client can respond with any word he/she can think of. ________ set-response options are provided for the client (multiple choice test). ______ response-client is free to respond or not. ______ Response-client must say something. [Forced choice = closed set forced response.]

Phonetically Balanced Word Lists selection of a group of words so that each phoneme appears with the same frequency it has in the normal lexicon. Based on Thorndike-Lorge lists of words and word frequencies. So-called PB word lists-- CID W-22 Lists Four lists of _____ words each.

CNC Word Lists Consonant-Nucleus-Consonant words ___________ balanced Four 50-item lists: the NU-6 Word Lists

Alternative Speech Choices High Frequency Word Lists –Gardner’s Hi Frequency Word Lists –California Consonant Test Nonsense Syllable Lists –The Nonsense Syllable Test (NST) Sentence Tests –The Synthetic Sentence Identification (SSI) test –Speech Perception in Noise (SPIN) test –Connected Speech Test (CST)

Children’s Tests Word Intelligibility by Picture Identification (WIPI) test – ___ pictures to choose from. Northwestern University Children’s Perception of Speech (NUCHIPS) test – ____ pictures to choose from Monosyllable-Spondee-Trochee test – distinguishing word shapes, not identifying particular words; used in ___________ cases.

WIPI Sample Item

NU-CHIPS Sample Item

Performance-Intensity Functions PI function: word recognition scores obtained at a range of stimulus levels. Curve reaches a peak (Pbmax), and then Either remains high (_________), or Drops at higher levels (________) Rollover Index = (PBmax – Pbmin)/PBmax

Rollover Indices for the preceding examples Normal: ( ) / 100 = 0.0 Rollover: ( ) / 44 = 0.54 Cochlear: ( )/80 = Rollover Indices of 0.45 or greater indicate a ___________________.

Cross Hearing & the Need to Mask If Word level (HL) TE – IA > Best BC NTE Use _______ (Speech) Noise, or _______ noise EM = PBHL TE – IA + ABG NTE

Interpreting Word Recognition Scores Score: General Word Recognition Ability: 90 to 100Within Normal Limits 75 to 90____________________ 60 to 75Moderate Difficulty 50 to 60__________ < 50Very poor

Predicting WRS from the audiogram: The AI The __________ Index __________ Index “Count the dot” audiogram If word recognition is poorer than prediction: think neural hearing loss or central disorder.