Chapter 9 Auditory Perry C. Hanavan, Au.D.

Major Divisions of the Ear Peripheral Mechanism Central Mechanism Outer Ear Middle Ear Inner Ear VIII Cranial Nerve Brain

Pinna

Function of Outer Ear Collect sound Localization Resonator Protection Sensitive (earlobe) Other?

Outer Ear Resonance Influence of pinna (p) Influence of ear canal (c) Combine influence (t) At 3000 Hz, the final amplification (t) is 20 dB

Pinna The visible portion that is commonly referred to as "the ear" Helps localize sound sources Directs sound into the ear Each individual's pinna creates a distinctive imprint on the acoustic wave traveling into the auditory canal

External Auditory Meatus Extends from the pinna to the tympanic membrane About 26 millimeters (mm) in length and 7 mm in diameter in adult ear. Size and shape vary among individuals. Protects the eardrum Resonator Provides about 10 decibels (dB) of gain to the eardrum at around 3,300 Hertz (Hz). The net effect of the head, pinna, and ear canal is that sounds in the 2,000 to 4,000 Hz region are amplified by 10 to 15 dB. Sensitivity to sounds greatest in this frequency region Noises in this range are the most hazardous to hearing

Outer Ear Resonance Influence of pinna (p) Influence of ear canal (m) Combine influence (t) At 3000 Hz, the final amplification (t) is 20 dB

Middle Ear Tympanic Cavity Tympanic Membrane Ossicles Virtual Tour of the Ear Middle Ear Cavity Ossicles Middle Ear Muscles Mastoid Eustachian Tube Function Amplifier Tympanic Cavity Tympanic Membrane Ossicles Middle Ear Muscles Eustachian Tube Mastoid

Function of Middle Ear Conduction Protection Transducer Amplifier Conduct sound from the outer ear to the inner ear Protection Creates a barrier that protects the middle and inner areas from foreign objects Middle ear muscles may provide protection from loud sounds Transducer Converts acoustic energy to mechanical energy Converts mechanical energy to hydraulic energy Amplifier Transformer action of the middle ear only about 1/1000 of the acoustic energy in air would be transmitted to the inner-ear fluids (about 30 dB hearing loss)

Transformer/Amplifier Area ratio Thumbtack Lever crowbar

Area Ratio

Middle Ear Muscles Tensor tympani Stapedius Attached to malleus Innervated by V, trigeminal nerve Stapedius Attached to stapes Innervated by VII, facial nerve Middle Ear Muscle Function: Protect inner ear from excessive sound levels When ear exposed to sound levels above 70 dB, the muscles contract, decreasing amount of energy transferred to inner ear

Inner Ear Auditory Vestibular Virtual Tour of the Ear Vestibular semicircular canals utricle and saccule Cochlear traveling wave Auditory Vestibular

Organ of Corti

Hair Cells Outer Hair Cells Inner Hair Cells OHC movie

Hair Cells Outer Hair Cells Inner Hair Cells OHC movie

Traveling Waves Traveling wave Basilar membrane Traveling Wave info Cochlear Traveling Wave

Basilar Membrane: Tonotopic

VIII CN: Afferent Neurons

OHC: Motile/Amplifier

Basilar Membrane: Tonotopic

VIII Cranial Nerve Auditory Branch Vestibular Branch Virtual Tour of the Ear Auditory Branch Vestibular Branch Spiral ganglion Acoustic Tumors

Major Divisions of the Ear Central Mechanism Brain Temporal Lobe Midbrain Brainsem

Temporal Lobe: Tonotopic

Central Auditory Path

Speech Perception How do we perceive speech? Individual sounds (phonemes)? Syllables? Words? Sentences? How do we derive meaning from the ocean of sounds we hear? Speech is variable Speakers vary in speech Variant or invariant cues?

Taking Statistics

"gaaaa" slowly turn into "water"

Perception of Phonemes

Audibility

Liberman and colleagues (1957) showed a phoneme boundary effect: Alvin Liberman (1917 – 2000) Liberman and colleagues (1957) showed a phoneme boundary effect: A smaller change in delay was necessary to distinguish /b/ from /p/, than to distinguish two phonemes within these categories.

The phoneme boundary effect Motor theory of speech perception: The phoneme boundary effect is caused by activation of the motor program required to produce a phoneme.

Category boundary effects in the colour domain Question: Is the way we sense colour affected by the words for colours in our language? Benjamin Lee Whorf (1897-1941)

Color can be objectively measured in terms of its wavelength: The question about colour perception can be operationalized: Color can be objectively measured in terms of its wavelength: 400n m 550nm 700nm Wavelength

Not subsumed by another term. The question about colour perception can be operationalized: The number of basic color terms in a language can be measured. Basic color terms are: Single words. Not subsumed by another term. Not restricted to a particular class of objects.

Dani (New Guinea): Two basic colour terms - mili (light), mola (dark). Early research on color naming Different languages have a variation in the number of words for colour categories. Dani (New Guinea): Two basic colour terms - mili (light), mola (dark). English: eleven basic color terms – white, black, grey, red green, blue, yellow, orange, purple, pink, brown.

Compared English and Tamahumara speakers. Kay and Kempton (1984) Compared English and Tamahumara speakers. Tamahumara does not make a distinction between blue and green. Kay and Kempton theorized that the perceptual distance between blue and green would be exaggerated in English speakers.

3 green G G G 2 green, 1 blue G G B B 3 blue B B Kay and Kempton (1984) 3 green G G G 2 green, 1 blue G G B B 3 blue B B

Kay and Kempton (1984) Tamahumara speakers were equally likely to choose either extreme for all three types of triplet.

Kay and Kempton (1984) English speakers were the same when all chips came from the same category. When there was an odd one out, they were more likely to choose that one.

Perception of Vowels /a/ vowel has greatest intensity with unvoiced /θ/ as weakest consonant Front vowels perceived on basis of F1 frequency and average of F2 and F3, whereas back vowels are perceived on the basis of the average of F1 and F2, as well as F3 So is it the absolute frequency values of the formants? Or the ratio of F2 to F1? Perhaps it is the invariant cues (frequency changes that occur with coarticulation F1/F2 F3 F1 F2/F3

Invariant and Variant Cues Showing how onset formant transitions that define perceptually consonant [d] differ depending on the identity of the following vowel. (Formants highlighted by red dotted lines; transitions are the bending beginnings of the formant trajectories.) /di/ /da/ /du/

Perception of Diphthongs Perceived on basis of formant transitions Salient feature: rapidity of transition

Consonant Perceptions Perception different for consonants than vowels Greater variety of consonant types than vowels Greater complexity for consonants

Question Which is TRUE regarding the following statements about categorical perception? Experience of percept invariances in sensory phenomena that can be varied along a continuum. Can be inborn or can be induced by learning. Related to how neural networks in our brains detect the features that allow us to sort the things in the world into separate categories All the above are true All the above are false

Categorical Perception Experience of percept invariances in sensory phenomena that can be varied along a continuum. Can be inborn or can be induced by learning. Related to how neural networks in our brains detect the features that allow us to sort the things in the world into separate categories  area in the left prefrontal cortex has been localized as the place in the brain responsible for phonetic categorical perception

Categorical Perception

Identification/Recognition Hearing loss affects the ability to correctly identify or label sound(s) Vowels relatively easy Consonants more difficulty to identify Place of production errors common High frequency consonants (sibilants) extremely difficult to identify

QuickSin/BKBSIN SNR Loss

UWO Plurals Test Test designed to test high frequency consonant detection, and assist with determining audibility.

Phoneme Perception Test

CI CI offers one treatment option Phonak remote Dynamic FM best for classroom noise conditions Currently, addition of classroom amplification with CI with FM shows no benefit

Siemens Hearing Test (Free)

iOS: iTalkAtMoog

Ling 6 (iOS)($1.99)

Cochlear HOPE Words Lite and HD

Cochlear HOPE App (Apple) Cochlear HOPE program Adopted from Speech Sounds and Speech Sounds Vowels Listen to a word and matching their speech production to what they heard. Vocabulary development also facilitated Each letter of alphabet has twenty different flashcards In some instances, letter may have two different speech sounds (for example, “A” as in “way” or “A” as in “cat”)

Baldi (iOS App $4.99)

Auditory Verbal iPad ($3.99)

Generate distortions

Hearing Aids Hearing aids FM remote microphones Phonak Dynamic FM best for background noise conditions Extended high frequency bandpass hearing aids (250-10,000 Hz) Non-linear frequency compression hearing aids

Phonak Dynamic FM Recievers

Non-linear Freq Compresion

Classroom Amplification Phonak Dynamic FM Phonak Dynamic FM in Classroom

Otitis Media Prevalent among children birth to 6. At-risk children for OM: Down Syndrome Cleft Palate (cranial facial) Treacher-Collins (cranial facial) 2nd-hand smoke Day-care Low income (Inner city, Native Americans, etc.) Bottle fed rather than breast fed Allergies Other infections (upper respiratory) Immune suppression (HIV, AIDS, etc.) Pacifier Family history

OME Tendencies Language impairments Poor phonetic processing At-risk for developmental delays in perceptual and phonemic awareness, thus leading to difficulties with higher level language functioning and reading

Specific Language Impairment Characterized by difficulty with language that is not caused by: known neurological, sensory, intellectual, or emotional deficit. Can affect the development of: vocabulary, grammar, and discourse skills, with evidence that certain morphemes may be especially difficult to acquire (including past tense, copula be, third person singular).

SLI (cont.) Children with SLI may be intelligent and healthy in all regards except in the difficulty they have with language. They may in fact be extraordinarily bright and have high nonverbal IQs. Children with SLI usually learn to talk late child 3 or 4 years of age with limited vocabulary and short utterances. Likely to be the kinds of kids who are told by parents and teachers they are smart but unmotivated and they just need to try harder.

SLI (cont.) Difficulty processing rapid acoustic speech cues (temporal processing problem) Difficulty identifying formant transitions, thus difficulty identifying phonemes Children of the Code Paula Tallal (Temporal spectral deficits)

Dyslexia Categorical perception difficulty Reading ability is significantly lower Difficulty perceiving consonant contrasts Confuse sounds phonetically similar May have deficits in processing the temporal order of acoustic information (difficulty identifying phonemes and judging the order in which the phonemes are heard) Difficulty segmenting, discriminating and identifying speech sounds

Types of Dyslexia Developmental phonological dyslexia - difficulty with nonword reading. Changing the initial and middle letters of a word. Examples are mana (mama) and aufo (auto). Developmental surface dyslexia - difficulty in reading irregular words. 25% English words are irregular, which means that they violate English spelling-to-sound word rule. Examples: pretty, bowl, and sew.

Etiology of Dyslexia Heredity: Family gene carries the disorder Studies have shown that males are four times more likely to have a reading disorder than a female; However, perhaps a male’s behavior contributes to this as it brings forth the disorder to a teacher’s attention more easily. Perhaps females can more readily compensate

Etiology of Dyslexia Environment: Limited English vocabulary English as second language students. Difficulty understanding phonemics. Children of poverty Children with parents with low reading levels Students with speech or hearing impairments

Articulatory Problems Categorized into subgroups: 1. Those with speech perception difficulties 2. Those with normal speech perception Subjects asked to identify words that contrasted phonemes /s/ and /S/. In this test, a subgroup of articulation-disordered children were unable to identify the test stimuli appropriately (seat vs. sheet). Subjects asked to identify words that contrasted the phonemes /s/ and /theta/, In words sick and thick, and none of the articulation-disordered children were able to identify these words appropriately whereas children without disorder could. Important to assess speech perception abilities prior to initiating articulation therapy Rvachew S & Jamieson DG. (1989). Perception of voiceless fricatives by children with a functional articulation disorder. J Speech Hear Disord.; 54(2):193-208.

Reading Disorders Difficultly reading or understanding material within a reading. Most have problems with their phonemic (sound/symbol relationships) awareness development. Have difficult time putting together letters to make a sound.