Glossary of Acoustic Terms

　Understanding acoustic terminology is essential for navigating the complexities of sound management and design.Below is a glossary of key acoustic terms and their definitions.

　A

　•Absorption:The process by which a material,object,or surface reduces sound energy by converting it into heat.

　•Acoustic Panel:A sound-absorbing panel used to reduce noise and control sound reflections in a space.

　•Ambient Noise:The background noise present in an environment,such as traffic,HVAC systems,or natural sounds.

　•Amplitude:The height of a sound wave,determining its loudness.

　B

　•Bass Trap:A type of acoustic absorber specifically designed to manage low-frequency sound energy.

　•Broadband Absorber:An acoustic material or device that absorbs a wide range of frequencies.

　C

　•Clarity:The ability to clearly hear individual sounds or speech without interference from reverberation or noise.

　•Critical Distance:The distance from a sound source where the direct sound and the reverberant sound are equal in intensity.

　•Crossover Frequency:The frequency at which sound is divided between speakers or drivers in an audio system.

　D

　•Decibel(dB):A unit used to measure the intensity of sound.

　•Diffusion:The scattering of sound waves to reduce echoes and create a more even sound distribution.

　•Direct Sound:Sound that travels directly from the source to the listener without reflecting off surfaces.

　E

　•Echo:A distinct repetition of sound caused by reflection from a surface.

　•Equalization(EQ):Adjusting the balance of frequencies in a sound system to achieve desired audio quality.

　F

　•Frequency:The number of sound wave cycles per second,measured in Hertz(Hz),determining the pitch of a sound.

　•Flutter Echo:A rapid series of echoes caused by sound bouncing between two parallel surfaces.

　H

　•Harmonics:Multiples of a fundamental frequency that contribute to the timbre of a sound.

　•Hz(Hertz):The unit of frequency,measuring the number of sound wave cycles per second.

　I

　•Impact Noise:Sound resulting from physical impacts,such as footsteps or dropped objects,typically transmitted through structures.

　•Insulation:Materials used to block the transmission of sound between spaces.

　L

　•Low-Frequency Noise:Sounds with frequencies below 250 Hz,such as bass tones or industrial hums.

　•Loudness:The perception of sound intensity,influenced by amplitude and frequency.

　N

　•Noise Floor:The level of background noise in a system or environment.

　•NRC(Noise Reduction Coefficient):A rating that measures the sound absorption of a material,ranging from 0(no absorption)to 1(complete absorption).

　P

　•Pitch:The perceived frequency of a sound,determining how high or low it sounds.

　•Porous Absorber:A material,such as foam or fiberglass,that absorbs sound by trapping it in its porous structure.

　R

　•Reverberation:The persistence of sound in a space after the source has stopped,caused by multiple reflections.

　•RT60:The time it takes for sound to decay by 60 decibels in a space,used to measure reverberation.

　•Reflection:Sound bouncing off a surface,contributing to echoes and reverberation.

　•Resonance:The amplification of sound at specific frequencies,often causing vibrations.

　S

　•Sabin:A unit of sound absorption,representing the absorption of one square foot of a perfect absorber.

　•Soundproofing:Methods or materials used to block sound transmission between spaces.

　•STC(Sound Transmission Class):A rating that measures a material’s ability to block sound transmission.

　T

　•Timbre:The quality or character of a sound that distinguishes it from others,even at the same pitch and loudness.

　•Transmission Loss(TL):The reduction in sound energy as it passes through a material or structure.

　V

　•Vibration Isolation:Techniques used to prevent vibrations from transferring through structures,often with pads or mounts.

　•Volume:The perceived loudness of sound,often influenced by its amplitude.

　W

　•Wavelength:The distance between two successive crests of a sound wave,inversely related to frequency.

　•White Noise:A sound that contains all audible frequencies at equal intensity,often used for masking unwanted noise.

　Conclusion