AUD 6400 Perception of Speech Sounds

What are the three basic parameters of speech perception?

Intensity, frequency, timing

What is intensity?

loudness

What is the basic perceptual ability of our auditory system (range processed without discomfort)?

0-120 dB SPL

What is the average intensity of speech at a distance of 1 meter?

45-60 dB SPL

How does perception of minimal intensity vary?

It varies as a function of frequency, auditory response area and distance from speaker

What is the inverse square law?

For every doubling of distance from sound source, intensity decreases by 6 dB

What factors affect intensity?

Distance, phoneme (vowel vs consonant), gender, and individual variations

What is the basic human perceptual ability for frequency?

20-20,000 Hz

What is the frequency range for speech?

50-10,000 Hz

What type of phoneme gives volume to speech?

low frequency vowels

What type of phoneme gives clarity to speech

high-frequency consonants

What type of phoneme has a longer duration?

vowels

What are the three speech audiometry measures?

Speech recognition threshold, speech awareness threshold, word reception score

What is the purpose of speech audiometry?

to cross check pure tone results, measure speech thresholds, information on communication function, central auditory processing, counseling tool

What is speech recognition threshold?

presentation of spondee words to determine lowest level where speech can be discriminated

How close should the SRT be to the PTA?

SRT should be within 10-12 dB of PTA

When could a picture board be used for SRT?

With young children or those who cannot verbally respond

What is a speech awareness threshold?

lowest level where patient can detect speech, when you can’t get SRT

Where do you start SAT testing for adults?

Start lower and have the patient tell you when they start to hear the word

Where do you start SAT testing for pediatrics?

Start higher and go down until patient doesn’t respond

What is word recognition score?

A suprathreshold test that screens for rollover and is sued for counseling in realistic expectations of communication

What materials should you use for WRS?

recorded materials

What is the stimuli for WRS?

monosyllabic phonetically balanced words presented at a fixed suprathreshold level (80 dB)

What is sensation level?

level of sound above a person’s SRT, presentation level - SRT

What is rollover?

decrease in speech recognition ability with increasing level of high intensity, indicative of retrocochlear disorder

How do you screen for rollover?

present at a high intensity level to tax the nerve, if there is no response decrease the level to see if WR improves

What are factors that affect speech audiometry?

response format, stimulus presentation, vocab and sophistication of test, presentation level (has to be outside of HL), signal to noise ratio

What is open-set response format in WRS?

not known to the patient, phonetically balanced words, does not provide choices

What is closed-set response format in WRS?

fixed number of items that are known to the patient (picture pointing, familiarized spondee words, digits)

What are issues with speech testing?

learning effects, test-retest variability, clinical significance (may not correlate with real life experience)

What is signal to noise ratio?

relationship between auditory signal we want to hear to all other unwanted background sounds, level of signal relative to background noise

How do you figure out the signal-to-noise ratio?

SNR= signal (desirable) - noise (undesirable)

always record as a positive or negative value