Issues in Classroom Acoustics

1
Issues in Classroom Acoustics

• Adequacy of the Communication Environment and
  Teaching in the Dark
• John Erdreich, PhD, FASA and
• R. Kring Herbert, FASA, INCE Board Certified.
• Ostergaard Acoustical Associates

2
Why the Concern?

• Aspects of energy efficient design
• Addition of noisy computer equipment
• Recognition of needs of population with
  disabilities
• New testing including verbal abilities

3
Plan of the Workshop

• Provide the scientific validation of the concern
• How acoustical engineers evaluate a space
• How to select criteria

• How to achieve criteria
• Activities re ADA
• Incorporating acoustics in to the design process
• Specialized spaces

4
Two Perspectives

• Occupational work environment
• Noise exposure
• Vocal pathology
• Classroom communication
• Speech intelligibility
• Language acquisition
• Effect of hearing impairment in children

5
Standards for Classroom Ambient Conditions

• Light
• Temperature
• Air changes
• Humidity

6
Areas for Acoustical Control

• Room finishes
• Activity sound
• Ventilation noise
• Sound intrusion from other rooms

7
Rationale for Acoustical Control

• Language development
• Communication by hearing impaired children
• Prevalence of hearing impairment in the school
  population

8
Relationship Between Hearingand Learning

• Hearing impairment in school-age children
• Differences in speech perception with hearing
  impairment

9
Normal Vs. Impaired Hearingin Children

• Normal 15 dB HL 500, 1000, 2000, 4000 Hz
• Auditory disorders
• Conductive
• Sensorineural
• Mixed
• Central

10
Impaired Speech Perception in Non-optimal
Listening Conditions

• Non-native English speakers
• Language deficits
• Attention deficit disorder
• Minimal SNHL
• Bilateral SNHL

• Conductive hearing loss associated with OME
• Normal hearing with history of OME
• Unilateral hearing impairment
• Learning disabled

11
Intervention Strategies Require Optimal Classroom
Acoustics to Be Effective

• Audiometric screening
• Preferential seating
• Personal hearing aids
• FM systems
• Soundfield FM systems

12
Comparison of Word Recognition NORMAL vs SNHL
13
Improvement in Recognition With Age
14
Sentence Recognition Performance With Age
15
Comparison of Noisy vs. Quiet Ventilator

• Quiet NC 30
• Noisy NC 50