The Apple Watch Ultra is the company's attempt at making a ruggedized fitness tracker designed for extreme sports, shown in its emergency features — the Apple Watch Ultra is the only Apple Watch to feature an 86-decibel emergency, Siren. Through the many iterations of Apple Watches over the years, Apple has asserted market dominance in the consumer smartwatch space. The company has viewed the smartwatch as a fitness and health product first and foremost, which is made clear by features like heart rate and blood oxygen sensors. However, the standard Apple Watch hasn't penetrated the extreme sports and fitness smartwatch market, which is precisely the company's target sector with the Apple Watch Ultra.
Siren is far from the first Apple Watch feature designed to alert first responders in an emergency. Every Apple Watch ships with an Emergency SOS mode that can call for help and notify family members during an emergency. These potentially life-saving features often go unnoticed but can be critical if needed. Holding the power button on an Apple Watch for five seconds will activate Emergency SOS and contact the relevant authorities. For cellular Apple Watches, this will work anytime there is a connection; Apple Watches without cellular must be in the range of an iPhone for Emergency SOS to work.
While Emergency SOS is useful for contacting first responders and relevant authorities in an emergency, the Siren is designed with an entirely different purpose in mind. The Siren is exclusive to the Apple Watch Ultra and uses larger — and more — speakers. The Siren produces an 86-decibel sound intended to alert people nearby to a person in distress. This works well when there is limited or no cellular connectivity. For example, if a hiker takes a fall and needs help, the Siren can alert people nearby to the hiker's location. But can the Apple Watch Ultra really produce a sound that loud?
How Loud Is The Ultra's 86-Decibel Siren?
After the Siren is activated, it produces a continuous 86-decibel sound that repeats at set intervals. The Siren will keep playing until the Apple Watch Ultra's battery runs out or the wearer shuts it off. Apple says the Siren is loud enough to be heard up to 600 feet away in certain situations. For reference, the 86-decibel sound is comparable to that of a blender or milling machine in operation, according to a study by Purdue University. It cycles between two different sounds that are recognizable and not typically found in nature to alert passersby to an emergency.
Depending on the Apple Watch Ultra's battery percentage when the Siren is activated, it can last up to several hours. It cycles between a primary sound intended to be a distress signal and a version of the universal SOS pattern. When the Siren plays, it will also cycle between volumes to produce a distress sound that ascends in volume. Due to the loudness of the Siren, it is only recommended for use in an emergency. Holding the Siren near a person's ear or playing it indoors could damage hearing. The Apple Watch Ultra's Siren is another smartwatch feature that users hope will never be needed but could be life-saving in an emergency.
Source: Apple, Apple Support, Purdue University