Dodo Youyou Hearhear Meme?Dodo Youyou Hearhear Meme?

The Listening EnvironmentThe Listening Environment

Molly Lyon, M.A., CCC-A/SPMolly Lyon, M.A., CCC-A/SPLSLS AVEdLSLS AVEd

Via Christi HospitalsVia Christi HospitalsJanuary 21, 2011January 21, 2011

ObjectivesObjectives

Participants will understand the concept of Participants will understand the concept of acoustic access and its importance in acoustic access and its importance in developing listening skillsdeveloping listening skills

Participants will become familiar with the Participants will become familiar with the environmental factors affecting auditionenvironmental factors affecting audition

Participants will learn about the application Participants will learn about the application of using FM technology in childrenof using FM technology in children

Listening in ChildrenListening in ChildrenSome Food for Thought…Some Food for Thought…

Children do not know what they don’t hearChildren do not know what they don’t hear Children do not expend the mental energy Children do not expend the mental energy

to comprehend a degraded, low intensity to comprehend a degraded, low intensity speech signal comprised of vague, speech signal comprised of vague, unfamiliar wordsunfamiliar words

They do not “go back” in auditory space They do not “go back” in auditory space and try to figure out what they didn’t hear and try to figure out what they didn’t hear

Children do not hear and process oral Children do not hear and process oral language at adult-like levels until around age language at adult-like levels until around age 13 13

Language acquisition is a work in progressLanguage acquisition is a work in progress As language and worldly knowledge increases As language and worldly knowledge increases

the less reliant we are on precision hearingthe less reliant we are on precision hearing Adult: 10% earwork and 90% brainworkAdult: 10% earwork and 90% brainwork Child: 90% earwork and 10% brainworkChild: 90% earwork and 10% brainwork

TransparencyTransparency

For young listeners, the speech signal For young listeners, the speech signal must be crystal clear, or “transparent” must be crystal clear, or “transparent” before true and optimal comprehension before true and optimal comprehension and language growth can occurand language growth can occur

The listening environment is critical to the The listening environment is critical to the development of auditory skills development of auditory skills

PrerequisitesPrerequisites

Assuming the child has been fitted with Assuming the child has been fitted with HA/CIHA/CI

Assuming the technology is programmed Assuming the technology is programmed optimallyoptimally

Assuming the child is wearing the HA/CI Assuming the child is wearing the HA/CI all waking hoursall waking hours

Little ears are now ready to listen, but…Little ears are now ready to listen, but…

A Moving TargetA Moving Target

HEARING LOSS is the only handicapping HEARING LOSS is the only handicapping condition in which the disabling effect is condition in which the disabling effect is in a constant state of flux.in a constant state of flux.

The negative impact of hearing loss can The negative impact of hearing loss can range from being nearly nonexistent to range from being nearly nonexistent to completely rendering an individual’s completely rendering an individual’s ability to use audition useless.ability to use audition useless.

What is Acoustic Access?What is Acoustic Access?

The degree to which spoken language is The degree to which spoken language is audible to a child audible to a child

Goal: 100% of the speech signal is Goal: 100% of the speech signal is audible 100% of the dayaudible 100% of the day

Acoustic access is under Acoustic access is under

ADULT CONTROLADULT CONTROL

Environmental Factors Affecting Environmental Factors Affecting Acoustic AccessAcoustic Access

NOISENOISE

DISTANCEDISTANCE

REVERBERATIONREVERBERATION

Background NoiseBackground Noise

Speech-To-Noise ratio (S/N) is criticalSpeech-To-Noise ratio (S/N) is critical Relationship between the primary signal Relationship between the primary signal

(speech) and background noise.(speech) and background noise. Noise sources include other talkers, heating Noise sources include other talkers, heating

or cooling systems (HVAC), timers, bells, or cooling systems (HVAC), timers, bells, alarms, computer hums, CD’s, radios, TV’s, alarms, computer hums, CD’s, radios, TV’s, wind, pets, etc.wind, pets, etc.

Homes are typically quieter than Homes are typically quieter than classroomsclassrooms

Allowable Signal-to-Noise Allowable Signal-to-Noise RatiosRatios

Adults with normal hearing require a S/N Adults with normal hearing require a S/N ratio of +6 dB (approximately twice as loud ratio of +6 dB (approximately twice as loud as background noise)as background noise)

Children with hearing loss require a S/N Children with hearing loss require a S/N ratio of +15 to +20 dBratio of +15 to +20 dB

DistanceDistance

Sound is degraded as it is propagated Sound is degraded as it is propagated through spacethrough space

Rapid Speech Transmission Index (RASTI Rapid Speech Transmission Index (RASTI study, Leavitt and Flexer, 1991)study, Leavitt and Flexer, 1991)

Integrity of a speech signal was measured Integrity of a speech signal was measured at 17 different distancesat 17 different distances

RASTI ResultsRASTI Results

Approximately 4 feet – RASTI score 83% Approximately 4 feet – RASTI score 83%

(critical speech information lost = 17%)(critical speech information lost = 17%)

Approximately 25 feet – RASTI score = 45%Approximately 25 feet – RASTI score = 45%

Perfect RASTI score was only able to be Perfect RASTI score was only able to be obtained at a distance of 6 inches from the obtained at a distance of 6 inches from the RATSI transmitter.RATSI transmitter.

Distance and DecibelsDistance and Decibels

Double the distance, Double the distance, lose 6 dB of intensitylose 6 dB of intensity

Every decibel is Every decibel is critical to children with critical to children with hearing losshearing loss

DistanceDistance DecibelDecibel

6”6” 60dB60dB

12”12” 54dB54dB

2’2’ 48dB48dB

4’4’ 42dB42dB

8’8’ 36dB36dB

16’16’ 30dB30dB

32’32’ 24dB24dB

Reverberation (Echo)Reverberation (Echo)

DEFINITION:DEFINITION: The time it takes in seconds from the The time it takes in seconds from the

moment a sound is stopped until the moment a sound is stopped until the sound level has diminished 60dB.sound level has diminished 60dB.

Affects of ReverberationAffects of Reverberation

Normal hearing adults can adequately Normal hearing adults can adequately discriminate speech in reverberations discriminate speech in reverberations times of .75 to 1 secondtimes of .75 to 1 second

Children with hearing loss require Children with hearing loss require reverberation times of .5 seconds reverberation times of .5 seconds

Anechoic chamber = 0 seconds Anechoic chamber = 0 seconds

Typical classroom = 1.6 secondsTypical classroom = 1.6 seconds

Reverberation IssuesReverberation Issues

Reverberant sounds mask high frequency Reverberant sounds mask high frequency soundssounds

Greater absorption of high frequency than Greater absorption of high frequency than low frequency soundslow frequency sounds

Elongations of vowelsElongations of vowels Smears transitionsSmears transitions Eliminates silent gapsEliminates silent gaps

Boothroyd DemonstrationBoothroyd Demonstration

DistanceDistance NoiseNoise ReverberationReverberation

Boothroyd, A., Phonic Ear Sound field Boothroyd, A., Phonic Ear Sound field tutorial 1.4a Room Acoustics and Speech tutorial 1.4a Room Acoustics and Speech Perception: The BasicsPerception: The Basics

FM Use in ChildrenFM Use in Children

Significantly improves and maintains Significantly improves and maintains speaker’s voice over background noisespeaker’s voice over background noise

Eliminates effects of distanceEliminates effects of distance

Reduces effects of reverberationReduces effects of reverberation

Child is able to receive consistent speech Child is able to receive consistent speech signalsignal

Listen …Listen …

Hearing Aid only Hearing Aid + FM

FM mic only

Soundfield Demonstration

BibliographyBibliography

American National Standards Institute. (2002). American National Standards Institute. (2002). Acoustical performance criteria, design requirements, Acoustical performance criteria, design requirements, and guidelines for schools and guidelines for schools (S12.60-2002). New York: (S12.60-2002). New York: American National Standards Institute (ANSI S12.60).American National Standards Institute (ANSI S12.60).

Boothroyd, A. (2004). Room acoustics and speech Boothroyd, A. (2004). Room acoustics and speech perception. perception. Seminars in HearingSeminars in Hearing, 25(2), 155-166., 25(2), 155-166.

Cole, E.B., and Flexer, C. (2008). Cole, E.B., and Flexer, C. (2008). Children with hearing Children with hearing loss: Developing listening and talking birth to sixloss: Developing listening and talking birth to six. San . San Diego, CA: Plural Publishing.Diego, CA: Plural Publishing.

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Davis, J. (Ed.). (1990). Davis, J. (Ed.). (1990). Our forgotten children: Hard-of-Our forgotten children: Hard-of-hearing pupils in the schoolshearing pupils in the schools. Bethesda MD: Self Help for . Bethesda MD: Self Help for Hard of Hearing People.Hard of Hearing People.

Flexer, C. (2004). Flexer, C. (2004). The impact of classroom acoustics: The impact of classroom acoustics: Listening, learning and literacyListening, learning and literacy. Seminars in Hearing, . Seminars in Hearing, 25(2), 131-140.25(2), 131-140.

Northern, J.L., & Downs, M.P. (2002). Northern, J.L., & Downs, M.P. (2002). Hearing in Hearing in childrenchildren (5 (5thth ed.). Baltimore: Lippincott Williams & ed.). Baltimore: Lippincott Williams & Wilkins.Wilkins.