Importance of Sound Quality in Public Places

Have you ever been in a cinema and wondered: “Wow, what an amazing sound quality!”, or on the contrary, been in a mall and public announcement speaker starts broadcasting and the terrible quality of sound immediately makes you (and everybody around) feel annoyed? Building a public place with a high-quality sound system takes a lot of efforts. You need some tools and an understanding of sound and its behavior in different environments.”Audio Generator” is a device that can be very helpful in designing great room acoustics. Nothing, more than room acoustics, can make or break sound output quality. You may have the best instruments, speakers, amplifiers and recording devices, and you may have put it all in your space correctly, but if your environment has poor acoustics, you are facing an uphill battle.

Intelligibility of speech

The degree of which a hearer can decode a signal created by a speaker. Intelligibility of speech is related to a number of fields, such as phonetics, human factors, acoustic design and audiometry. Human speech is unique in that, compared to the consonants, the vowels or voiced sounds from the vocal chords produce most sound power. But consonants, though lower in strength, hold the information necessary for separating similar sounding words from one another. Consonants are voiceless sounds produced in the mouth with contribution of the tongue, teeth, and lip. Note how you form certain consonants, such as P, T, and B, C, and Z, S, and F, or M and N. Note also how clearly you can talk and retain a vowel sound as opposed to a consonant.

What you should do is build a space that is neither too “live” nor too “dead”. A room that is “live” is a room where smooth, reflective surfaces predominate. Lots of glass windows open, hardwood flooring, stuff like that. The room sounds like your gymnasium at the high school — which seem to echo things forever. Such repeated echoes make it difficult in the music to differentiate between individual instruments and vocalists. Other extreme is an overly damp “dead” space: thick-pile carpeting, heavy ground-to-ceiling curtains, and dense, overfilled furnishings. A space like this sounds like you’re stuck in a tiny winter-coat closet.

How well you can understand a spoken message in a room is affected by some conditions:

Background noise

There are many types that noise can take. Noise as you would hear from building HVAC systems, street traffic, sirens or percussive noises like jack hammers and natural sounds like wind, rain or ocean waves. But noise that disrupts speech intelligibility could also take the form of many people talking simultaneously, resonances in a room, music, and problems of equipment such as hums and buzzes.

Reverberation

The continuity of sound after the sound is made. A reverb is produced when a sound or signal is reflected which causes multiple reflections to build up and then fade out as the sound is absorbed by object surfaces in area – which can include furniture, people and air.

Distortion

The changing of original form (or other feature) of something. In our case, the shift in the waveform of an info-bearing signal, such as the sound-representing audio signal. Distortion is typically undesirable and therefore engineers aim to remove it or reduce it.

Now lets talk about the device that will help us overcoming this obstacles:

Audio Generator

A signal generator (also called the oscillator) is a device that produces electronic signals, recurring or non-repeating, in either the analog or digital form. These generated signals will be used as a stimulus for electronic tests, usually used for designing, measuring, troubleshooting, equipment maintenance, and repairing electronic or electroacoustic devices, although they often have also artistic uses.

The Speech Transmission Index (STI) is a common standard indicator for the consistency of speech intelligibility. By using an audio generator, you can measure important aspects of sound design to achieve STI standard. Some of those aspects are:

• Reverberation Time: Checks environment acoustics for optimal efficiency of the device and speech intelligibility.
• Delay: Setting of acoustic delays for improved output of the surround sound.
• Polarity: All speakers shall be tested for the same polarity and thus obtaining a large stereo or surround sound picture.
• FFT Analysis: Study of reflections and cancellations to enhance the architecture of the space and the intelligibility of words.

Minirator MR-PRO/MR2 are two great Analog Audio Generators with a wide range of measurable noises, manufactured by NTi Audio Company.