Bathroom noise is an issue of running water, flushing toilets, and people—well, you know what they are doing! Auditory privacy can be an important factor in designing a bathroom, especially in one that is centrally located in a home, or near the social or living areas. In addition, noises in a bathroom near a bedroom can seem especially loud and disturbing when someone is trying to sleep.

Noise is often defined as unwanted sound. Therefore, controlling noise is a matter of limiting the transfer of sound from one part of the home to another. Sound moves by vibrations, which are
transmitted through both air and building materials. Soft materials, such as carpet and draperies, tend to absorb sound. Hard materials, such as the ceramic tile and stone, that are common in bathrooms, tend to reflect and/or transmit sounds. Bathroom noise is controlled, and auditory privacy provided, in several ways:

• Reducing the amount of sound or noise that is generated

• Isolating and buffering the sources of noise through space planning

• Using construction techniques to insulate and stop sound transmission

Reduce Noise Generated

Many bathroom features generate noise. Bathroom ventilation fans are necessary to control mois­ture, yet motors and air movement can be noisy. The importance of selecting quiet bathroom fans with a minimum sone rating is discussed in chapter 7, "Mechanical Planning," with other informa­tion about bathroom ventilation. A fan that generates too much noise simply will not get used.

Jetted tubs may offer stress-relief and rejuvenation but are not silent in operation. As tub and motor size, and the volume of water movement, increase, the potential for noise grows.

Laundry areas (discussed in chapter 9, "More Than a Bathroom") are sometimes included in the bathroom. Noise transmission, especially to the sleeping area, should be a consideration in the placement and installation of washers and dryers.

Motors, such as those used in ventilation fans, jetted tubs, and washing machines, may vary in pitch (hertz). Many people perceive lower pitch noises to be less annoying. However, it is important for your client to "test listen" to different motors to determine their reaction to the noise.

Pressure-assisted toilet flushing systems minimize the use of water while increasing flushing ef­fectiveness, but the sudden rush of water can seem loud. Noise complaints about the mandated low-flush toilets have been frequent, but manufacturers continue to improve the product. How­ever, toilets that use air pressure to assist the flush tend to be noisier.

Buffer the Noise

If you have the opportunity to influence the home design beyond just the bathroom space, you can help buffer the bathroom space, and reduce sound transmission. Look for ways to put sound­absorbing spaces between the bathroom and quiet areas of the home. For example, a closet be­tween a bathroom and a bedroom is an excellent way to buffer bathroom noise and keep sleeping areas undisturbed. Other spaces that make good sound buffers are built-in cabinets, bookshelves, stairways, and utility closets.

Another sound-buffering space planning technique is to back noisy area to noisy area. For exam­ple, put the toilet on the wall that is shared with the kitchen rather than the wall that is shared with the bedroom.