With regard to buzzers, since they have an apparent sound hole either on the top or at its side, so it’s easy for water to drop in. Hence, buzzers are not water-protected. Fortunately, buzzers are usually placed internally deep in the product, secured and far from the water in the outer environment, so the risk is very low. Either DIP or SMD package, the buzzers are situated on the PCB, which is by most design insulated from water. In case the PCB is water-insulated by a layer of epoxy, please ensure that the epoxy doesn’t touch or cover the buzzer, especially the buzzer’s hole. One might worry if the user can’t hear the buzzer’s beep clearly if the buzzer is sealed inside the product’s enclosure. Based on experience, sound can still travel to the outside via mechanical vibration and other means of sound transduction. This is especially true for a buzzer with high mechanical quality factor, which AATC is capable of designing.

Even if the buzzer is connected with wires and put near the surface of the product’s housing, you can still rest assured. It’s because these kinds of buzzers are usually piezo buzzers, and the piezo plates in it are very robust. Made of ceramic piezo-electric material, the plates are fairly resistant to liquid and dust. The only cautions are to ensure the plate’s glue are properly applied and it isn’t degraded by any heat. Products like piezo-electric MEMS microphone uses these kinds of ceramic diaphragms to achieve higher IP ratings.

With regards to micro-speakers, although they have no apparent sound holes, they’re not usually waterproof either. The term rather preferred in the speaker industry is “water-resistant”. Consider the front side, if the diaphragm is made of paper and if the paper isn’t coated, then it can still soak in water. If the surround is not tightly glued with the basket, then the water can still intrude in small gaps between. On the other hand, if the back of the volume is tightly sealed, then it can possibly prevent water. The only thing to remember is to make sure the small venting holes on the back is meshed with waterproof material. If there’s a big venting port on the back, then one might try to cover the hole with a passive radiator to stop water ingress. In conclusion, by implementing special design, AATC can offer truly IP-67, waterproof micro-speakers.

With regards to microphones, the common way is to add mesh on its front side. To achieve stricter IP rating, one can implement some mechanical adjustments, such as making a twisted and bending path in front, to prevent water from directly falling inside. Or simply make the sound holes face downward and as small as possible, since most water comes from the above. Or one can misalign the mic sound holes and the housing sound holes, also to prevent water from directly falling in.