Audio Frequency range of humans

Pitch is the subjective term for Frequency

Human speech is mainly in the range

Prolongation of the sound in the room caused by continued multiple reflections

Bass sound is considered

Treble sound is considered

The sound energy transferred per second from the noise source to the air

Sound pressure converted to the decibel scale

The human impression of the strength of a sound

Used to absorb the vibration of the generator base

Expressed in units called watts (W)

One octave increase doubles the frequency

A logarithmic scale applicable to any parameter.

Safe exposure limit for human reception for eight hours a day

Bending or “flowing” of a sound wave around an object or through an opening

The fraction of the randomly incident sound power which is absorbed, or otherwise not reflected.

Ceiling that can diffuse sound

Scattering or random redistribution of a sound wave from a surface

Absorbs sound and keeps it too (thermal storage)

Absorbs sound and transmits excess sound to the next room

A single-number index for rating how absorptive a particular material is

A value given in decibels, which is determined by measuring sound pressure levels at a certain frequency in the source and receiving rooms.

Sound reflected on two-focus points

Sound reflected on one focus points

A reflection with magnitude and delay

Caused by repetitive reflections off hard surfaces

This is a single-number rating of a material’s or assembly’s barrier effect.

Material with the lowest STC rating

Material with the highest STC rating