Speech Production and testing Flashcards
What is quick SIN?
A diagnostic ‘speech in noise’ test which tests the signal to noise ration loss
Ie how much do we need to boost signal so patient can hear over noise
What is the quick SIN methodology?
6 sentences containing 5 key words
Presented at prerecorded SNR ratio
Decrease 5dB with each sentence
Normal to severely impaired performance in BGN
Defaults to 70dB but can be changed dependent on HL
What are the quick SIN presentation levels?
identify PTA average:
Up to 45dB = 70dB
55. 80-85
65. 90-95
75. 100-105
Ie 25-30 above their PTA average
What are the SNR results for quick SIN?
0-3. Normal hearing
4-7. Mild SNR loss mild issue in BGN
8-15 moderate SNR loss
15+ severe SNR loss
The greater the loss the better HA technology required
Record results on diagnostic page in CMS
What are the types of speech issues that we can test using speech testing? (5)
Retro cochlea
Auditory ability - disparity between ears
Non organic hearing ie noise induced
Child testing
Hearing aid benefit
Name the different speech tests for adults?
Speech recognition threshold test
Speech discrimination tests
Arthur Boothroyd
Acceptable noise level
Audibility index audiology
Speech shaped noise
HH consultation - speech test
What is the speech recognition threshold test?
Spondee words 2 equal words together ie eardrum airplane schoolboy etc
Word presented patient repeats
If correct increase by 10dB with another word
If wrong decrease by 5dB until heard
Need 3 out of 6 for each ear
Should be within 10dB of PTA average
Describe the speech discrimination test.
Phonetically balanced words used: equally difficult, common use and monosyllabic.
Called the ‘fry’ list.
Do the results match PTA?
Can identify asymmetrical loss
What is the Arthur Boothroyd test?
Uses 3 letter consonant-vowel-consonant words for adults add older children.
10 words - 1 point given for each letter correct. Maximum 30 points available.
Patient repeats what they think has being said.
Describe the acceptance noise level (ANL) test.
Field free - recorded voice through loudspeakers.
A speech passage (story) and noise
ANL = MCL - BNL
Patient listens to story, volume set at their MCL.
Gradually introduce noise to the story until patient reports maximum Levi they could listen to story and still understand speech (background noise level BNL)
The lower the score the better chance of a good fitting.
Explain the audibility index audiogram.
COUNT THE DOTS!!
A speech intelligibility index we count all the dots BELOW the hearing threshold (each ear) to determine score.
Dots strategically placed within specific points of speech bubble/banana
What is the speech shaped noise test?
White noise used to block cochlea. White noise is same intensity across all frequencies.
With SSN patient will capture some sounds as intensity is WEIGHTED across frequencies to mimic speech sounds.
HH speech test?
Unaided-field free-live voice
List of balanced words
Max 10 words
Patient closes eyes & repeats what they hear
Score out of 10
What is speech?
A process of uttering ARTICULATED sounds.
A complete feedback process in which hearing, perception and information processing in the nervous system and the brain are also involved.
Explain harmonics add timbre
A harmonic is a sound wave that has a frequency that is a multiple (whole number) of a fundamental tone - the lowest frequency of that sound.
2nd harmonic (f2) freq twice that of fundamental
4th harmonic (f4) four times that of fundamental frequency.
Harmonics and overtones to a wave that make possible to distinguish between sounds and instruments - known as timbre
What is a Formant?
It is the acoustical energy concentrated around a particular frequency in speech.
Vocal cords set up secondary vibrations (harmonics) which enhance some frequencies more than others.
These enhanced frequencies are Formants.
Why is noise often heard as low frequency?
Noise contains a mix of frequencies but high frequencies do not travel well due to being a shorter wavelength, therefore, lose their energy and thereby intensity sooner.
What is frequency analysis?
This breaks a frequency down into its component parts ie the different frequencies that make up a sound - the more frequencies the more complex the sound.
What is the SNR? When does it become positive, negative or equal?
Signal to noise ratio.
It is the balance between the signal strength and the BGN strength.
To hear speech in noise clearly the signal needs to be equal or more than the noise signal depending on the HL.
It is a DECIBEL VALUE.
If signal is stronger than noise it is POSITIVE.
If it is weaker than noise it is NEGATIVE.
0dB SNR is where they are equal.
Conductive loss needs 0dB SNR as long as the SNR is above their hearing threshold. Ie a 30dB conductive loss would require a 0dB SNR to be at 30dB.
A SN loss typically needs SNR to be POSITIVE PLUS 10dB.
What is the Lombard effect?
Simply that the voice will naturally amplify with the intensity of noise ie to ensure will be heard over the noise.
What are the 4 key elements of speech production? Explain the function of each.
RESPIRATION - provides energy for sound by using air pressure (exhalation) from the lungs.
PHONATION - vibrating vocal chords via rapid opening and closing of the chords.
RESONANCE - air pressure and added vibrations now resonate in the vocal tract (air cavity above the Chords that extends to the lips)
ARTICULATION - lips, tongue, jaw and soft palate of mouth are used differently to make different sounds - the SPEECH SIGNAL.
Describe the journey of the speech signal from lungs to lips.
As we exhale this pushes the air out with more force which travels up the trachea to the larynx (voice box) causing vocal chords to rapidly open and close causing vibrations.
Vocal cords elongate - longer produces low frequency and shorter produces high frequency. It is the length of the vocal cord that determines the RESONANT frequency.
These vibrations then enter the vocal tract air cavity where they resonate.
Male vocal tract is low freq around 120Hz and female/child 220Hz higher frequency.
The articulators then shape the sound to produce speech.
What are the most effective resonators?
1st Pharynx
2nd mouth
3rd nose
Speech sound is divided into two types - what are they and what differentiates between them?
VOICED: produced in larynx by means of expelled air from lungs and VIBRATED by the vocal cords.
VOICELESS: exactly the same but they are NOT VIBRATED by the vocal cords.
What are vowel sounds and how do they differ from consonants?
Vowels is air from the lungs not blocked by the mouth or throat (consonants are)
Vowels are always VOICED.
What is the average speech intensity?
Relate this to the inverted square law.
Approximately 65 dB at a distance of 1 metre. However, fluctuation of 12dB between quietest and loudest sounds.
Relate: the intensity to the inverted square law ie 6dB loss as you double the distance.
Intensity is always proportional to the distance squared.
How do recognise speech sounds?
Speech is a series of sounds made into words.
Phonemes are individual sounds, the smallest unit of speech.
Then syllables
Then words
Then sentences
Ie PLANET
6 phonemes
2 syllables
1 word
0 sentence
What are the 3 types of consonants? Describe them.
NASAL: M, N, NG mouth closed, sound out of nasal cavity.
PLOSIVES: vocal tract blocked somewhere then air pressure released.
Voiced: P K T voiceless: B D G
FRICATIVES: voice Tract narrow, air forced through.
Voiced S F voiceless Z V
Which sounds do we hear better? Why?
Vowels are low frequency soo heard well whilst consonants are high frequency soo hard less well.
BGN is generally low frequency so this increases the chances of the quieter, high frequency consonants not being heard.
REMEMBER: low equals volume/Power high frequency is clarity.
What aspects of hearing loss will affect speech production?
Type and degree of HL
severity of the loss
Nature of onset and it’s progress
Duration elapsed before HA’s.
What are the key stages in human speech development?
4-6 months babbling
7-11 months tuneful babbling
12, months couple of words
18-24 mths 2 words together
2 years building lines ‘me do it’
3 years 5-7 word sentence
3 plus using ‘ing’ words plurals etc when speech issues can be identified.