Lecture 10- Pediatric Audiology Flashcards
Why are classroom acoustics important?
Students may spend at least 45% of the day in activities requiring listening
Central auditory system doesn’t reach full maturity until early adolescence
o Children in school are listening with immature auditory systems
Factors that affect a student’s ability to hear the intended message
○ Integrity of the listener’s auditory system
○ Intensity of signal (teacher’s voice)
○ Reverberation properties of the room
○ Background noise present
(The last 3 can be controlled to some extent)
What are the characteristics of classroom acoustics (3)?
- Intensity and Distance
- Background Noise
- Reverberation
What is typical background noise in a classroom?
Children are inherently “noisy”
Some noises are unavoidable (e.g., HVAC, hallway noise, traffic or lawn mower outside)
○ But may be able to be managed
Some noises are avoidable (e.g., class aquarium)
Combined effects of various noise sources create more difficulty in a classroom environment
What is reverberation?
- Reflected sound energy
- Occurs when sound continues in a space due to repeated reflection or scatter from the surfaces &/or objects in that space
- RTs longer than 0.5 seconds appear to degrade speech recognition for most listeners in educational environments
- RTs for unoccupied classrooms range from 0.4 to 1.2 seconds (Crandell, 1992; Knect et al., 2002)
Describe the relationship between the signal, background noise, & reverberation.
Combined effects are synergistic
○ More problematic than the sum of individual effects
When SNR decreases in a classroom, speech intelligibility decreases for students
SNR in typical classrooms is anywhere from +5 to -7 dB
What are the ANSI standards for classroom acoustics?
Unoccupied classroom levels must not exceed 35 dBA
SNR must be at least +15 dB at the child’s ears
Unoccupied classroom reverberation must not surpass:
o 0.6 seconds in core learning space with a volume < 10,000 ft3 or 0.7 seconds in larger rooms
o 0.7 seconds in core learning space with a volume >10,000 ft3 and <20,000 ft3
Why are classroom acoustics usually poor?
Some classroom designs are inherently poor listening environments
Open-plan/ open concept classrooms
- Fewer of these are being built but many still exist
Tall ceiling made of hard material (e.g., plaster), hard walls, and many hard surfaces
- Hard surfaces tend to increase reverberation times to the point where speech intelligibility is difficult even for the best listeners
What are the desirable classroom acoustics?
- Install sound-absorptive material on ceiling and walls
- Place a rug or carpeting on the floor
- Constructing the midsection of the classroom’s ceiling with hard surfaces to reflect sound to the back of the classroom
What are some solutions to improving classroom acoustics?
- Reduce or eliminate unnecessary noise sources
- Apply sound absorbing surfaces to ceilings & walls
- Install carpet on floors of classrooms
- Construct classrooms with good acoustic properties
- Reduce the listening distance between the teacher and the students
- Encourage the use of sound field amplification in the classroom
Are HATs available with a 504 plan?
- Inconsistency in terms whether assistive tech is provided under 504
- Section 504 requires public schools to provide students with disabilities appropriate educational services designed to meet their individual needs to the same extent of students without disabilities
Ed. AuD could argue that a D/HH student doesn’t have the same access to auditory info without a personal FM
What are some verification procedures?
May differ depending on whether the FM is used with a hearing aid, CI, bone-anchored device, or by itself
Electroacoustic analysis
Real ear
Behavioral procedures
○ Speech recognition in noise w/ & w/o FM
What are some validation procedures?
Objective and subjective measures
○ Self-assessments
○ Observation questionnaires (teachers & parents)
○ Functional evaluations completed in the student’s learning environment
How can the AuD train teachers, students, and school staff?
- Basic function of the device (e.g., on/off)
- Appropriate use of the device (e.g., when it should be used)
- Care and maintenance
- Basic troubleshooting
- School AuDs should frequently check in with students and personnel to ensure consistent, proper device use.
How can FM be used for sound transmission?
A specific band of frequencies has been set aside for personal FM systems in the US
○ Older systems used 72-76 mHz, newer systems use 216-217 mHz
AuDs need to keep a record of which FM channels are being used at any given time ○ E.g., if student A is on channel 01, student B can’t use it at the same time. ○ If 2 students are in the same class and using one transmitter may use the same channel
What is classroom sound field amplification?
Mainstream Amplification Resource Room Study (Ray, 1988) showed:
o Improved SNR
o Less vocal fatigue for teachers
o Improved academic achievement
Infrared or FM Sound transmission?
