Speech Reverberation Times :

1
Speech Reverberation Times
Association of Classroom Volume to Reverberation
Time.
The Grammies
Mike Christoff Lauren Wise Mark Blaser
2
Reverberation
The time it takes for a sound to decay (a
predetermined amount) from the moment when sound
production stops.
The study of reverberation times within a space
can be done in a few different ways.

• Analyzing existing conditions by measuring
  sounds.
• Calculating (estimating) what conditions should
  or could be.

3
Hypothesis
Reverberation time of a room will become longer
as the room volume increases.
Testable Hypothesis
Reverberation time in the second floor classroom
will be longer, due to the increased ceiling
height and type of construction, than the first
floor classroom.
4
Research Outline

• Choose frequency to conduct study --- 539.9 Hz
• Fundamental frequencies of human voice fall
  between 100-600 Hz
• Collect data using digital recorder
• Analyze data using Gram11 software to obtain
  frequency graphs.
• Use excel to chart specific frequency (539.9)
  over time.
• Use information from charts to establish
  reverberation times of the classrooms.
• Relate classroom information found to
  appropriate reverberation levels in rooms of
  similar functions.

5
Measuring Existing Conditions
Second Floor Classroom
First Floor Classroom
6
Section Through Classrooms
First Floor Classroom
7
First Floor Classroom
8
Second Floor Classroom
9
First Floor Classroom
43.398 Seconds 67 dB 43.618 Seconds - 36
dB .22 2 .44 Seconds Reverberation Time (T30)
Second Floor Classroom
43.418 Seconds 80 dB 44.519 Seconds - 50
dB 1.101 2 2.202 Seconds Reverberation Time
(T30)
10
Conclusion
The reverberation times in the larger volume room
were increased significantly enough to extend the
reverberation time beyond what can be considered
appropriate for a classroom environment (for the
second floor classroom).