Ah, the hustle and bustle of busy city living, where nothing sleeps, and things always happen. Around every corner, an exciting adventure awaits, like a scene straight out of a movie. From the clattering subway beneath your feet to the symphony of sirens, chatter, and laughter that fills the air, a contagious vibrancy sweeps you up in its relentless tide and pulsating energy of big-city living. Welcome to the metropolis, where dreams are brewed under nonstop hustle and bustle.
Statista1 notes that in 2020, about 83 percent of the United States population lived in cities and urban areas. It may appear extreme, but other countries and regions, like Hong Kong, Kuwait, and Singapore, have entire populations in urban areas.2
This global process of urbanization—where the percentage of people living in cities is growing faster than the percentage in rural areas—has led to many changes, some with negative consequences. This is especially true in countries and cities where the population grows faster than the infrastructure. In addition to the decrease in air quality due to fossil fuel emissions and the safety and health issues due to the large volume of organic and non-organic waste, there is the issue of noise pollution.
Noise or sound pollution is the excessive and sometimes harmful levels of noise closely associated with urban living. This is due to the high concentration of human activity like automotive traffic, construction, factory work, and loud music. This constant exposure to loud noise can disrupt human life, contributing to sensory overload and serious health issues. For instance, prolonged exposure to high-decibel noise can result in noise-induced hearing loss. Noise pollution, especially at night, can interrupt the sleep cycle, leading to insomnia or other sleep disorders. Lack of quality sleep can result in fatigue, decreased productivity, and workplace accidents. Continuous exposure to high noise levels can also increase stress and irritability and reduce quality of life. Noise pollution hinders learning and concentration, leading to decreased academic performance.
With growing noise pollution in cities, urban residents desire ways to lessen unwanted noise at home. A viable solution is whole-house noise cancellation. This article delves into whole-house noise cancellation and its potential to enhance urban living quality.
Noise-canceling technology works by combining two sounds in a way that each cancels the other. In a phenomenon referred to as destructive interference, two sound waves of the same amplitude but out of phase from each other are combined so that the peak of one wave matches the trough of the other. This inversion completely cancels both sound waves, resulting in a quieter environment (Figure 1).
Figure 1: Active Noise Cancellation (ANC) technology works by actively countering incoming noise with opposite sound waves. The key principle is the concept of destructive interference. (Source: Mouser Electronics)
Many people are familiar with noise cancellation through their headphones' Active Noise-Cancellation (ANC) technology, which uses a microphone to sense external noise and then emits the inverse sound wave(s) to cancel it. The same principle can be applied to whole-house noise-canceling systems. These systems use microphones to detect unwanted noise in a room or throughout the entire house. The systems can be set to cancel out a specific frequency or multiple frequencies, depending on the noise source.
There are two main types of whole-house noise-canceling systems: active and passive.
ANC systems are more commonly used for whole-house applications, as they are more effective than passive systems at canceling out low-frequency sounds such as traffic noise or airplane sounds. To cancel out these sounds, a system must emit a sound wave with the same or greater amplitude, which can be achieved by using multiple speakers throughout the house.
The placement of these speakers is crucial to the effectiveness of a system. The speakers should be strategically placed in areas where noise levels are high, such as near windows facing a busy street. They should also be placed in areas clear of obstructions such as furniture or walls, which can interfere with the sound waves.
Remember, this whole process is done almost instantaneously, which is what makes it so effective for real-time noise cancellation. It is important to note, however, that ANC is most effective at canceling steady, low-frequency sounds like the hum of an airplane or air conditioner. It's less effective at eliminating abrupt, high-frequency noises like people talking or dogs barking.
Passive noise-canceling systems, on the other hand, are more suitable for reducing high-frequency noise, such as voices or the sound of appliances in the home.
This approach of whole-house noise cancellation implements soundproofing techniques and sound-absorbing materials, such as acoustic tiles, to reduce the reflection of sound waves in a room. This reduces the overall noise level in the room, making it more comfortable to work, sleep, or relax. This approach is particularly important in homes with shared walls or in areas where noise levels are particularly high, such as near an airport or train station. The effectiveness of passive noise-canceling systems depends on the type and thickness of the sound-absorbing material used. The material should be placed strategically throughout the room, particularly in areas where sound waves reflect, such as corners or against walls. Other forms of passive noise-canceling systems include drapery on windows, cubical partitions like you would find in an office environment, and rooms with carpet and few windows.
Furthermore, soundproofing techniques can also include the use of double-glazed windows, door seals, insulation, and even structural changes to the house. These techniques are particularly effective when combined with active or passive noise-canceling systems, as they prevent the transmission of noise from outside or between rooms.
This week’s New Tech Tuesday features offerings from CUI Devices and TDK. These products are uniquely suited for whole-house noise-canceling solutions and have been developed over the years by leading suppliers in the industry.
CUI Devices IPX-rated speakers offer exceptional quality and reliability for various applications. These speakers offer ingress protection ratings of IPX5, IPX7, IP67, and IPX8 and profile depths as minimal as 2mm for space savings design. These speakers are available in rectangular and round frames and include a variety of cone materials such as polyetheretherketone (PEEK), polyetherimide (PEI), polyethylene terephthalate (PET), and polyurethane (PU)+paper+PET. Additionally, these speakers are available in different sizes and mounting options and come in solder pad and spring contact. The RoHS- and REACH-compliant speakers' neodymium magnets ensure exceptional audio quality for your next audio design.
TDK InvenSense T583x Bottom Port Microphones are compact digital microphones with low noise. They consist of a MEMS microphone and an impedance converter amplifier followed by a fifth-order Σ-Δ modulator. These microphones support time multiplexing of two microphones' pulse-density-modulated (PDM) output on a single clock and data line. They come in a standard surface mount package (3.5mm × 2.65mm × 0.98mm) and offer various operating modes. TDK InvenSense T5837 and T5838 Bottom Port Microphones comply with RoHS/WEEE regulations.
Whole-house noise cancellation is a viable option for homeowners who want to minimize unwanted noise at home. Active noise cancellation systems effectively eliminate low-frequency sounds, while passive systems are better at reducing high-frequency noise. Proper placement of speakers and sound-absorbing materials is crucial, as is using soundproofing techniques to prevent noise transmission between rooms and outside.
For optimal effectiveness, careful planning and implementation are essential, along with working with experienced professionals in the field and using products like those offered by CUI Devices and TDK can help homeowners create a tranquil, comfortable, and healthy home environment shielded from urban noise.
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Rudy Ramos brings 35+ years of expertise in advanced electromechanical systems, robotics, pneumatics, vacuum systems, high voltage, semiconductor manufacturing, military hardware, and project management. Rudy has authored technical articles appearing in engineering websites and holds a BS in Technical Management and an MBA with a concentration in Project Management. Prior to Mouser, Rudy worked for National Semiconductor and Texas Instruments..