My friend has an acoustic 106 cabinet in the lounge

I have a friend who is in the music industry and he is obsessed with all the related paraphernalia such the best speakers, systems etc. I, on the other hand don’t care as long as I can hear the music I like on a relatively respectable system at home and in the car. When he starts to talk about his acoustic 106 cabinet, acoustic measuring equipment and acoustic calibrator, I just zone out. This doesn’t make him happy but he has learned to live with it!  

Analysis of sound and acoustic measurement plays a role in such engineering tasks as product design, production test, machine performance, and process control. For instance, product design can require modification of sound level or noise for compliance with standards from ANSI, IEC, and ISO. The work might also involve design fine-tuning to meet market expectations. Here, examples include tweaking an automobile door latching mechanism to impress a consumer with a satisfying click or modifying an exhaust manifold to change the tone of an engine's rumble. Aircraft designers are also using acoustic measurement equipment to reduce the noise generated on take-off and landing.

Acoustic measurements

Acoustics deals with the science of sound, the transmission of vibrations in gasses and solids. Although acoustics implies that you can hear signals, acoustics also deals with signals both below (infrasound) and above the highest frequencies of human hearing (ultrasound).

Measurements       

Acoustic measurements can deal with the purely scientific aspects of sound, such as acoustic pressure, energy, or sound power, but they can also be used to evaluate the annoyance (in the automotive industry, this is called noise, vibration, and harshness), hearing damage potential, or the quality of acoustic transducers such as loudspeakers and microphones.

Acoustical measurements and instrumentation range from a handheld sound level meter to a 1000-microphone phased array. Most of the acoustic measuring equipment can be broken down into three components:

·         Sensors

·         Data Acquisition

·         Analysis

Sensors

The most common sensor used for acoustic measurement is the microphone. Measurement-grade microphones are different from typical recording-studio microphones because they can provide a detailed calibration for their response and sensitivity. Other sensors include hydrophones for measuring sound in water or accelerometers for measuring vibrations causing sound. The three main groups of microphones are pressure, free-field, and random-incidence, each with their own correction factors for different applications.

 Units

            The following units are commonly used in acoustic measurements: dB, Pascal, dB (A), SEL.

Environments        

The most common acoustic measurement environment is a specialized test chamber that serves two main purposes:

·         Provides an environment where the relationship between sound power and sound pressure is well known.

·         Reduces or eliminates interference from intruding noises, such as environmental noises from the operation of support equipment, mechanical equipment, automobiles, trucks, aircraft, and rail traffic.

Listening to my friend over the years I have picked up a lot of information regarding sound, noise and acoustics but I still have no interest in learning more about the various types of acoustic measurement equipment and other such things that he talks about!