Current research at the MRC Institute of Hearing

Current research at the MRC Institute of Hearing

Current research at the MRC Institute of Hearing Research (Scottish Section) Michael A. Akeroyd [email protected] MRC Institute of Hearing Research (Scottish Section), Queen Elizabeth Building, Glasgow Royal Infirmary, 16 Alexandra Parade, Glasgow, G31 2ER. Co-funded by the MRC and by the Chief Scientist Office of the Scottish Government Health Directorates. Links 2 MRC Institute of Hearing Research

MRC Institute of Hearing Research (Nottingham ; Director = David Moore) Science & admin Scottish Section Links 3 MRC Institute of Hearing Research Medical Research Council. Funding & advice MRC Institute of Hearing Research (Nottingham ; Director = David Moore) Science & admin Scottish Section

Funding & advice Chief Scientist Office, Scottish Government. Links Medical Research Council. Funding & advice MRC Institute of Hearing Research (Nottingham ; Director = David Moore) Glasgow University. Science, Lecturing,

Strathclyde University. Staff, Students 4 MRC Institute of Hearing Research Science & admin Scottish Section Funding & advice Chief Scientist Office, Scottish Government. ENT,

Audiology NHS Glasgow Royal Infirmary. Links Medical Research Council. Funding & advice MRC Institute of Hearing Research (Nottingham ; Director = David Moore) Glasgow University.

Science, Lecturing, Strathclyde University. Staff, Students 5 MRC Institute of Hearing Research Science & admin Scottish Section Funding & advice Chief Scientist Office, Scottish Government.

ENT, Audiology NHS Glasgow Royal Infirmary. + staff + patients Overview We do fundamental and translational research on: what does a hearing loss mean for someone? how does it affect how they listen? what does it mean for their quality of life? what benefits do hearing aids offer?

who benefits from hearing aids? 6 MRC Institute of Hearing Research Prevalence For the population: About 1 in 5 adults has a bilateral hearing problem that affects their hearing and communication in Scotland thats about 750,000 people; About 1/4 of them would benefit from a hearing aid; About 1/5th of them (i.e., 1/5th of 1/4 of 1 in 5) have a hearing aid; 7 MRC Institute of Hearing Research Davis et al (2007) HTA Report; Executive Summary Prevalence

For the population: About 1 in 5 adults has a bilateral hearing problem that affects their hearing and communication in Scotland thats about 750,000 people; About 1/4 of them would benefit from a hearing aid; About 1/5th of them (i.e., 1/5th of 1/4 of 1 in 5) have a hearing aid; For the NHS: Around 1.5 2 million appointments per year ( 0.5 million patient journeys); 120 million per year; 700,000 hearing-aids fitted per year; Some 250,000 waiting for first-appointment or re-assessment (in 2006). 8 MRC Institute of Hearing Research Davis et al (2007) HTA Report; Executive Summary Prevalence of hearing loss

Those who said yes to Do you have any difficulty with your hearing? in a postal questionnaire (N = 31793) : By age-group 14 34 years 35 54 years 55 75 years Older than 75 7% 17% 32% 46% Everyone 19% 9 MRC Institute of Hearing Research

By occupation (55-75 years only) Manual Non-manual 43% 29% By gender (55-75 years only) Male Female 41% 23% Davis et al (2007) HTA Report What does a hearing loss mean?

Difficulties in communication & social function Talking to family or friends or colleagues; Conversations on telephone; Listening anywhere noisy (e.g. restaurants, bars) Difficulties in hearing & listening Travel announcements at airports or on trains; Dialogue at cinema, theatre, radio; Distance, direction, and motion of sounds;

Segregation and identification of sounds; Effort involved in listening. Difficulties in society reduced education and skills; reduced employment opportunities. Impairment, disability, handicap Auditory impairment = what goes wrong e.g. increase in absolute thresholds, wider auditory filters;

Auditory disability = consequences for auditory situations e.g. poorer ability to identify speech in noisy backgrounds; Auditory handicap = consequences for general life e.g. avoidance of noisy situations; (Almost) all you need know about spatial hearing You have two microphones (the ears) about 20 cm apart, with the gap filled by something solid and roughly spherical (the head). 12 MRC Institute of Hearing Research (Almost) all you need know about spatial hearing

You have two microphones (the ears) about 20 cm apart, with the gap filled by something solid and roughly spherical (the head). Your auditory system can work out Timing differences across the ears; Level differences across the ears; And it can concentrate on just the start of a sound, ignoring the rest. 13 MRC Institute of Hearing Research (Almost) all you need know about spatial hearing You have two microphones (the ears) about 20 cm apart, with the gap filled by something solid and roughly spherical (the head). Your auditory system can work out Timing differences across the ears; Level differences across the ears; And it can concentrate on just the start of a sound, ignoring the rest.

So having two ears means You can determine where a sound source is; Improve its detectability; Do better in complex auditory situations like rooms; 14 MRC Institute of Hearing Research What are the cues to direction? High frequencies: head casts an acoustic shadow; sound at far ear is quieter than at near ear (ILD) 15 MRC Institute of Hearing Research What are the cues to direction?

High frequencies: head casts an acoustic shadow; sound at far ear is quieter than at near ear (ILD) 16 MRC Institute of Hearing Research Low frequencies: tiny acoustic shadow (due to diffraction); sound at far ear is about same as at near ear; but it takes longer to get there (ITD) Threshold (Minimum audible angle) Thresholds for changes in spatial angle (pure tones) 12 10

Reference direction = 30 (to right) 8 6 4 Reference direction = 0 (straight ahead) 2 0 1000 Frequency (Hz) 10000

Best ITD threshold 10 ms. Best ILD threshold 1 dB. 17 MRC Institute of Hearing Research Grantham (1995), after Mills (1960) Rule of thumb for visual angles 10 2 the visual width of the fist held at arms length; the visual width of the thumb .. .. .. 1.5 the visual width of the thumbnail .. .. .. 1

the visual width of the index fingernail .. .. .. 0.5 arcminutes = 1/120 = best visual acuity 18 MRC Institute of Hearing Research RP OShea (1991) Thumbs rule tested Perception 1991 (20) 415-418 Rossi and Roorda (2010) Nature Neuroscience 13:156-157 Angles and people 10 2 the visual width of a person about 3-m distant; the visual width of a person about 15-m distant;

1.5 the visual width of a person about 20-m distant; 1 the visual width of a person about 30-m distant (Width of person (over shoulders) 50 cm) 19 MRC Institute of Hearing Research NASA: Anthropometric Source Book Vol I. pIII-33 subtendedangles1_28march2010.xlsx Spatial hearing, circa 1893 20 MRC Institute of Hearing Research http://www.psychologicalscience.org/observer/getArticle.cfm?id=2454a

Spatial hearing, circa 1936 21 MRC Institute of Hearing Research Stevens and Newman (1936) The 24-loudspeaker ring in Glasgow 22 MRC Institute of Hearing Research Motion tracking system (two cameras not shown) 23 MRC Institute of Hearing Research Motion tracking to sound 24 MRC Institute of Hearing Research

Brimijoin, McShefferty, Akeroyd (in press) Auditory and visual orienting responses in listeners with and without hearing impairment, JASA Motion tracking to sound Brimijoin, McShefferty, Akeroyd (in press) Auditory and visual orienting responses in listeners with and without hearing impairment, JASA Task: A random* speaker plays a sentence; Turn your head to it; * Not entirely random actually a very carefully controlled sequence that has every possible speaker and speaker-to-speaker jump in it; 25 MRC Institute of Hearing Research Press pageup twice to reset

Illustrative trajectories 26 MRC Institute of Hearing Research Brimijoin, McShefferty, Akeroyd (in press) Auditory and visual orienting responses in listeners with and without hearing impairment, JASA BSA poster 2009 Mean fixation positions 27 MRC Institute of Hearing Research Brimijoin, McShefferty, Akeroyd (in press) Auditory and visual orienting responses in listeners with and without hearing impairment, JASA BSA poster 2009

Velocity and latency 28 MRC Institute of Hearing Research Brimijoin, McShefferty, Akeroyd (in press) Auditory and visual orienting responses in listeners with and without hearing impairment, JASA JASA paper fig.5 JASA paper fig. 6 Complexity of trajectory 29 MRC Institute of Hearing Research Brimijoin, McShefferty, Akeroyd (in press) Auditory and visual orienting responses in listeners with and without hearing impairment, JASA

BSA poster 2009 Distance perception 30 MRC Institute of Hearing Research Distant source in room Time 0 Distance perception 31 MRC Institute of Hearing Research Distant source in room Time

0 Close source in room Time 0 Direct sound 32 MRC Institute of Hearing Research Akeroyd, Blaschke, Gatehouse (2007). The detection of differences in the cues to distance by elderly hearing-impaired listeners, J. Acoust. Soc. Am. 121:1077-1089. Direct sound + 1st reflections 33 MRC Institute of Hearing Research

Akeroyd, Blaschke, Gatehouse (2007). The detection of differences in the cues to distance by elderly hearing-impaired listeners, J. Acoust. Soc. Am. 121:1077-1089. Direct sound + 1st + 2nd reflections 34 MRC Institute of Hearing Research Full system uses 75 sounds: listener perceives a sound at the same distance as the real sound in the real room But The auditory world is complicated there is never just one sound coming from one direction* * unless you are in an anechoic room, etc.

The auditory world changes too sounds start, stop, move, & vary people fidgit, move, walk 35 MRC Institute of Hearing Research A noisy auditory environment 36 MRC Institute of Hearing Research Zoffany: The Academicians of the Royal Academy (1771) How many sounds can one locate at once? Task: 1 adult voice from one location; 1 child voice from a random location;

Where is the child? 37 MRC Institute of Hearing Research Childs voice In design !! Adults voice How many sounds can one locate at once? Task: 2 different adult voices from two locations; 1 child voice from a random location; Where is the child? 38 MRC Institute of Hearing Research

In design !! Childs voice How many sounds can one locate at once? In design !! Task: 8 different adult voices from many locations; 1 child voice from a random location; Where is the child? 39 MRC Institute of Hearing Research Childs voice

Woodfield & Akeroyd (submitted) The role of segmentation difficulties in speech-in-speech understanding in older and hearing-impaired adults Speech segmentation Segmented by the actual gaps in the signal: Thereare nos ilen ces bet weenword

s Segmented by the your speech & language systems: There are no silences between words but how well does speech segmentation work in hearing impaired adults? 40 MRC Institute of Hearing Research from Kuhl, 2004, Nature Reviews Neuroscience Speech segmentation Actual sentence Never just convict them (strong syllables are underlined) Example response

Never just conviction Deletion before weak syllable Stimuli from Cutler and Butterfield (1992) 41 MRC Institute of Hearing Research Woodfield & Akeroyd (submitted) The role of segmentation difficulties in speech-in-speech understanding in older and hearing-impaired adults Speech segmentation Actual sentence Woodfield & Akeroyd (submitted) The role of segmentation difficulties in speech-in-speech understanding in older and

hearing-impaired adults Actual sentence Never just convict them The hunters went fulfilled (strong syllables are underlined) Example response Example response Never just conviction Deletion before weak syllable

Stimuli from Cutler and Butterfield (1992) 42 MRC Institute of Hearing Research The hunters went for wool Insertion before strong syllable Speech segmentation 43 MRC Institute of Hearing Research Woodfield & Akeroyd (submitted) The role of segmentation difficulties in speech-in-speech understanding in older and hearing-impaired adults Type

Legend MSS? Insertions before strong Insertions before weak Deletions before strong Deletions before weak Group N Young NH Older NH Older HI 16 13 12

IS IW DS DW Yes No No Yes Mean Mean Age Hearing loss 24 59 62

(normal) 13 dB 33 dB Fig. 1 Speech segmentation 44 MRC Institute of Hearing Research Woodfield & Akeroyd (submitted) The role of segmentation difficulties in speech-in-speech understanding in older and hearing-impaired adults Fig. 1 Intensity Discrimination

or Whitmer & Akeroyd (submitted) Level discrimination of speech sounds by hearing-impaired individuals with and without hearing amplification Play a reference sound (standard interval) then play a slightly-more intense copy (test interval) Play a slightly-more intense copy then the reference sound 45 MRC Institute of Hearing Research Fig. 1

Intensity Discrimination or Whitmer & Akeroyd (submitted) Level discrimination of speech sounds by hearing-impaired individuals with and without hearing amplification Play a reference sound (standard interval) then play a slightly-more intense copy (test interval) Play a slightly-more intense copy then the reference sound Adaptively vary the amount of the increment depending how the person responds to which one is louder?

Continue until threshold for level difference is found. 46 MRC Institute of Hearing Research Fig. 1 An illustrative hearing aid Whitmer & Akeroyd (submitted) Level discrimination of speech sounds by hearing-impaired individuals with and without hearing amplification Microphone inputs Receiver (loudspeaker)

Telecoil (for induction loops) Microphones Selector switch Electronics (DSP chips) On-off switch 47 MRC Institute of Hearing Research Battery Output (to ear)

An illustrative hearing aid Whitmer & Akeroyd (submitted) Level discrimination of speech sounds by hearing-impaired individuals with and without hearing amplification Microphone inputs Receiver (loudspeaker) Telecoil (for induction loops) Microphones Electronics (DSP chips)

On-off switch 48 MRC Institute of Hearing Research Battery Output (to ear) Output level (dB) Selector switch Input level (dB) An illustrative hearing aid

Whitmer & Akeroyd (submitted) Level discrimination of speech sounds by hearing-impaired individuals with and without hearing amplification Microphone inputs Receiver (loudspeaker) Telecoil (for induction loops) Microphones Electronics (DSP chips) On-off switch

49 MRC Institute of Hearing Research Battery Output (to ear) Output level (dB) Selector switch r: n a i ne dB i L 0

1 10 dB t) u o ssion: e r t p m Co dB ou

3 in 10 dB Input level (dB) Intensity Discrimination 50 MRC Institute of Hearing Research Whitmer & Akeroyd (submitted) Level discrimination of speech sounds by hearing-impaired individuals with and without hearing amplification Values in brackets are medians

N = 37 (all aided) Mean age = 67 years Mean hearing loss = 55 dB Mean compression = x1.5 Fig. 4 Intensity Discrimination 51 MRC Institute of Hearing Research Whitmer & Akeroyd (submitted) Level discrimination of speech sounds by hearing-impaired individuals with and without hearing amplification Error bars are 95% c.i.

Fig. 5 Summary: What does a hearing loss mean? Difficulties in communication & social function Talking to family or friends or colleagues; Conversations on telephone; Listening anywhere noisy (e.g. restaurants, bars) Difficulties in hearing & listening

Travel announcements at airports or on trains; Dialogue at cinema, theatre, radio; Distance, direction, and motion of sounds; Segregation and identification of sounds; Effort involved in listening. Difficulties in society reduced education and skills; reduced employment opportunities. + impairment, disability, handicap

53 MRC Institute of Hearing Research The end

Recently Viewed Presentations

  • Lecture 3 - Physics and Astronomy | Physics and Astronomy | TTU

    Lecture 3 - Physics and Astronomy | Physics and Astronomy | TTU

    Red Line around Italy is animated to appear on mouse click. Point out London (England), Paris (France), Holland (where the Dutch people live), Germany, Spain, Switzerland, Africa red star is: Pisa, Italy (where Galileo was born) Jupiter and Its Moons...
  • Chapter 8: Revolution and Enlightenment

    Chapter 8: Revolution and Enlightenment

    Jean-Jacques Rousseau- most famous philosophe of the later Enlightenment. ... Traditional practices plus changes in art, music, literature. Rococo-art style that emphasized grace, charm, gentle action and was highly secular. Musical geniuses- Haydn and Mozart.
  • MESA SEGUIMIENTO DE LAS MEDIDAS DE IMPULSO COMPETITIVO

    MESA SEGUIMIENTO DE LAS MEDIDAS DE IMPULSO COMPETITIVO

    MESA SEGUIMIENTO DE LAS MEDIDAS DE IMPULSO COMPETITIVO DEL ÁREA PECUARIA. * * * e* * * * * * * * * * * * MESA PECUARIA Gobierno de Chile | Ministerio de Agricultura MESA PECUARIA Gobierno de Chile...
  • More About Matter - portnet.org

    More About Matter - portnet.org

    More About Matter Physical and Chemical Properties * * Density can change under different pressure and temperature conditions. This is especially true for gases which can expand and contract in volume easily. * Density Because all matter has mass and...
  • First-Year of College: Getting Them to Read Statement

    First-Year of College: Getting Them to Read Statement

    Reading Comprehension as an Integrative Learning Strategy in a Philosophy Learning Community. Chelsie Hawkinson & Dr. Rita Sperry. Texas A&M University - Corpus Christi
  • IHS/THP Eligibility and Enrollment Verification

    IHS/THP Eligibility and Enrollment Verification

    IHS/THP Eligibility and Enrollment Verification Subject: Review methods to apply for enrollment in VAHCS and ways IHS/THP facilities can verify American Indian/American Native (AI/AN) Veteran eligibility. Keywords
  • JSE PTS Media

    JSE PTS Media

    CPSS-IOSCO compliance (focus on liquidity, stress testing market conditions, enhancing risk management and reporting) Reduce the time it takes to settle from 5 days to 3 days (T+3) 4. Enable on-exchange clearing OTC Derivatives. 5. Implement risk models.
  • Copyright  2007 MES-English.com zero  one  two three  four

    Copyright 2007 MES-English.com zero one two three four

    zero one two three four five six seven eight nine ten eleven twelve thirteen fourteen fifteen sixteen seventeen eighteen nineteen twenty * * Title: Slide 1 Author: User Last modified by: a Created Date: 9/12/2006 12:54:36 AM Document presentation format: