Lecture 7 Flashcards
Why do we need to know about speech acoustics for individuals with hearing loss?
to know:
- what information is available through hearing
- how to make sounds more audible for listener
- when to compliment audition with other senses
- why someone speaks the way they do
- be able to provide better feedback to audiologist
What are the components that affect the acoustics of speech communication?
talker/speech production
- age
- gender
- accent
- language proficiency
environment/acoustic transmission
- distance
- noise
- room acoustics (reverberation)
listener/speech perception
- age
- hearing status
- language proficiency
- sensory aids
- non-acoustic cues
What is f0?
fundamental frequency
depends on mass, length, and tension of vocal cords
bigger/longer/less tense = lower (adult male)
smaller/shorter/more tense = higher (adult female or child)
What are harmonics?
multiples of f0
What are the important formants for speech perception?
F1 = first formant
F2 = second formant
different vocal tract shapes are created by different formants, therefore creating different sounds
What are segmentals?
vowels
- tongue high or low
- lips rounded or spread
- mouth opening
diphthongs
- vowel combinations, first gliding to second
consonants
- manner, place, voicing
What are suprasegmentals?
duration
intensity
pitch/frequency
must detect all 3 features to understand speech
carried by vowels
mostly found in F0 and F1
first features perceived by children learning how to listen - before consonants/vowels differentiated
At what frequencies are F1 and F2 information most accessible?
F1 most available below 1000 Hz
- most acoustic energy of speech
F2 most available above 1000 Hz
- major contribution to understanding of speech
How do F1 and F2 contribute to speech perception?
need both to identify a phoneme
F1 = required to be able to detect a phoneme
F2 = required to be able to identify a phoneme
How do vowels and consonants differ in suprasegmentals?
vowels are longer duration, louder, and lower pitch
How is whispering used as a tool in AVT?
can lower vowel intensity and allow better perception of consonants
loudness of vowels can mask consonants, whispering highlights them
What is the half square rule?
each time you half the distance between ear and sound source, sound power increases by 6 dB
each time you double the distance, sound power diminishes by 6 dB
when learning to listen, closer is better
- don’t just raise your voice
What are the 3 anchor vowels in AVT?
/u/, /a/, and /i/
different F1 and F2 combinations
What is the hierarchy of listening from basic to complex?
detection
- awareness of presence of a sound
discrimination
- determine whether 2 sounds are same or different
identification
- identify what sound is/naming
comprehension
- understanding meaning
What is the key difference between detection and identification?
detection = presence vs absence
- requires F1
identification = naming
- requires F2
How can we tell if someone can detect or identify vowels?
knowing where hearing loss is can determine if they have access to F1/F2 of different vowels, which can then determine if they can detect or identify them
Based on formants, what would happen for someone with higher frequency hearing loss? What information do we need to remember to determine this?
may have trouble telling vowels apart, especially if they have similar F1s
know the anchor vowels and and accompanying F1/F2, as well as the acoustic order of the vowels
Why is a speech acoustics cheat sheet important?
different segmental and suprasegmental features are heard at certain frequencies
manner cues, place cues, voicing cues, nasality, suprasegmentals, etc. all heard at different frequencies
How easily are acoustic cues of consonants heard?
manner and voicing = low frequency = easy to hear
place = high frequency = difficult to hear
What are the effects of co-articulation on speech perception?
transitions between sounds can make speech perception easier
What does it mean if formant transitions are larger?
make a place difference more audible
bigger = better
more contrast between formants makes sounds easier to perceive
- ex. in AVT, enhance perception of high frequency consonants by pairing with lower frequency vowels
What are the easiest and hardest to hear fricatives?
easiest/lowest = sh
highest = s
softest = f and voiceless th
How does distance affect ability to hear?
sounds will be softer and less clear
Which phoneme type is more important for speech perception?
consonants
How does noise affect ability to hear?
sound of target speaker will be drowned out
How does reverberation affect ability to hear?
sound of target speaker will be drowned out
How do we accommodate for distance, noise, and reverberation?
get closer or use an assistive listening device (ex. FM)
Should we focus on speech development or correction?
developmental approach for children <3 years
speech correction for children > 3 years
How can we enhance speech development in a child <3 years with hearing loss (beginning listener)?
lay a good speech foundation through listening
- then less likely to need to do speech correction later
sit right beside child, speak close to better ear
- at very close distance, whisper or use soft voice
do not emphasize lipreading
sing
use learning to listen sounds
bombard target sound
- no more than 1-3 speech targets at a time
say before see (so they hear before they see)
correct gently by highlighting the correct sound in the word
How can we enhance speech development in a child >3 years with hearing loss?
same techniques as for under 3’s
teach through audition as much as possible
if you need to use visual or tactile cues, bring sound into hearing awareness by repeating it using audition alone at least a couple times
