title: The effect of classroom amplification on the signal-to-noise ratio in classrooms while class is in session.
abstract: OBJECTIVE
  The purpose of this study was to measure the signal-to-noise ratios in classrooms while class was in session and students were interacting with the teacher and each other.
  
  
  METHODS
  Measurements of noise and reverberation were collected for 5 different classrooms in 3 different schools while class was in session. Activities taking place during the measurements were recorded to compare with sound level measures. The use of infrared classroom amplification was compared with no amplification.
  
  
  CONCLUSIONS
  The results revealed that when classroom amplification was used, students heard the teacher's voice at a level that was an average of 13 dB above the noise floor as compared to an average of +2 dB above the noise floor without amplification.
authors.affiliation: COMDDE Department, Utah State University, 1000 Old Main Hill, UMC 1000, Logan, UT 84322-1000, USA. Jeffery.larsen@usu.edu
authors.forename: Jeffery B
authors.initials: JB
authors.lastname: Larsen
authors.forename: James C
authors.initials: JC
authors.lastname: Blair
mesh_terms: D000328:Adult; D000669:Amplifiers, Electronic; D002648:Child; D005178:Faculty; D006801:Humans; D007374:Interior Design and Furnishings; D009622:Noise; D012574:Schools; D013018:Sound Spectrography; D013061:Speech Acoustics; D013065:Speech Intelligibility