It is the time in seconds required for a sound made in an enclosed space to diminish by 60 decibels.

• Reverberation

• Decay rate

• Reverberation Time

• Echo

It is the level of sound intensity high enough to cause pain and discomfort. Longer exposure to such sound can cause permanent damage to our hearing ability.

• Maximum allowable acoustic level (MAAL)

• Threshold of Pain

• Auditory fatigue

• Aural Comfort Limit

It is the phenomenon of persistence of sound after it has been stopped as a result of multiple reflections from surfaces such as furniture, people, air, etc. within a closed surface.

• Flutter Echo

• Resonance

• Echo

• Reverberation

It is a classification of sound that pertains to the “low-frequency sound waves with frequency below the limit of audibility of human.

• Infrasonic

• Subsonic

• Ultrasonic

• Supersonic

It is the term used to define the rapid succession of echoes caused by the reflection of sound waves back and forth between two parallel surface, with sufficient time in between to cause the listener to be aware of each reflected sounds’ separation

• Flutter Echo

• Flicker Echo

• Strobing Echo

• Oscillating Echo

It is the rate of decrease of sound pressure level after the sound has stopped. It is measured in decibels (dB) per second.

• Decay Rate

• Fade Rate

• Depressurization Rate

• Diffusion Rate

Refers to frequencies above 20,000 Hz (20,000 cycles per second). It is basically the sound waves with frequencies higher than the audible limit of human hearing.

• Hypersonic

• Supersonic

• Ultrasonic

• Infrasonic

If a typical bat can hear frequencies from 9Hz up to 120,000Hz, what is the audible limit (aka hearing range) of a human being? Frequencies beyond this limit is basically cannot be heard by us.

• 10Hz - 20,000Hz

• 20Hz - 20,000Hz

• 100Hz - 10,000Hz

• 200Hz - 20,000Hz

It is the type of sound that are periodic and somewhat regular

• Melodic

• Musical

• Notes

• Pitch

It is the reflection of sound, arriving at the listener sometime after the direct sound.

• Flutter Echo

• Reflected Sound

• Reverberation

• Echo