iPhones occasionally make an unexpected siren or alarm-like noise, which can be alarming or concerning for owners. This strange sound usually signifies that something is wrong with the device. While an iPhone siren may seem mysterious, there are just a few potential causes behind it.
This article will examine the main reasons an iPhone may make a blaring siren or alarm sound, so you can identify and troubleshoot the issue.
Amber Alerts
AMBER alerts on iPhones are emergency notifications that are designed to allow emergency services to request help from citizens under urgent circumstances. When a child is abducted, law enforcement can coordinate with cell phone carriers and broadcast providers to activate an AMBER Alert to quickly spread information about the missing child through wireless emergency alerts (WEA).
When an AMBER Alert is issued in your area, your iPhone will receive the alert and play a series of loud, attention-grabbing siren noises along with displaying information about the abduction on the screen. The siren is intentionally jarring in order to grab your attention in urgent situations where authorities need help locating an abducted child. According to Apple’s support page, “AMBER alerts are always critical emergency alerts. You can’t turn off AMBER alerts on your device.”
So in summary, the siren noise on iPhones for AMBER Alerts is designed to immediately notify citizens of urgent child abductions in their area so they can be on alert and assist law enforcement if possible. The loud, attention-grabbing siren aims to spread the information quickly and prompt users to read the alert details and contact authorities right away if they have any relevant information.
Emergency Alerts
The iPhone is capable of receiving Emergency Alerts issued by government authorities for events like severe weather, AMBER alerts for missing children, and other critical situations. These alerts are sent out directly by authorized government agencies and can override user settings to deliver critical safety information.
When an Emergency Alert is received on an iPhone, it will trigger a loud siren-like sound even if the phone is set to silent or Do Not Disturb. This is intentional in order to alert users to the emergency situation. The sound is meant to get the user’s attention so they stop what they are doing and read the alert message. This ensures critical safety information reaches as many people as possible.
Users cannot disable Emergency Alerts, as they are considered essential public safety messages. The siren sound gives an indication of the alert’s importance and urgency. After reading the message, users can dismiss the alert by swiping up from the bottom of the screen. The phone may continue to repeat the siren sound until the alert is acknowledged.
Alarm/Timer Expiration
One of the main reasons an iPhone may make a siren noise is when an alarm or timer that was previously set expires. The default alarm and timer sound on iPhone is a loud siren noise that plays at full volume even if your phone is set to silent or vibrate mode. This is an intentional design by Apple to make sure alarms can wake you up or alert you even if your phone is muted.
The iPhone alarm and timer siren sound is very loud and jarring by design. It starts slowly and steadily increases in pitch and tempo until it becomes a blaring siren. This ascending siren noise will continue playing on loop at full volume for one minute until you dismiss the alarm or timer.
To stop the alarm siren, you simply need to open your iPhone and swipe the “Stop” button when the alarm is sounding. For timers, opening the Clock app while the timer expiration siren is playing will allow you to stop the timer. So in summary, if you ever hear a loud siren noise from your iPhone, it likely means an alarm has expired and needs to be dismissed in the Clock app.
Source: https://support.apple.com/en-us/HT207512
Critical Battery Alert
One possible cause for an iPhone making a siren noise is the critical battery alert. This alert occurs when the battery level drops below 20% on iPhone models starting with the iPhone 6s and later (1). The critical battery alert produces a series of three loud siren noises at decreasing intervals to urgently notify you that the battery is critically low.
The alert cannot be disabled, as it is intended to prevent sudden shutdowns from an exhausted battery. Once triggered, the siren will repeat every few minutes until you charge the iPhone or it powers down due to the battery being fully depleted (2). The only way to stop the sound is to charge the iPhone or allow it to run out of power completely.
Powering Down
One potential cause of the iPhone making a siren noise is if the user is trying to force power down the device. When holding the side/power button to force turn off the iPhone, sometimes a loud siren sound may play instead of the device turning off (1). This appears to happen in situations where the iPhone has become unresponsive or ‘frozen’ and will not turn off normally.
The siren noise during forced restart seems to stem from an issue with the hardware or software not responding properly. Pressing and holding the side button is supposed to trigger a full shut down, but in some cases the iPhone gets stuck and emits a blaring siren instead. This has been reported on various iPhone models including the X, 11, and 12 (2).
If your iPhone begins blaring a siren when you attempt to force shut down, the recommended fix is to let go of the side button, wait a few moments, then hold the side and volume down buttons together to try forcing a restart instead (3). This siren noise indicates your iPhone has become unresponsive and needs a hard reset to get it functioning again.
Hardware Issue
A siren noise when trying to turn on your iPhone could indicate a hardware problem. Some potential hardware issues that could cause this include:
Faulty power or sleep/wake button – If the power or sleep/wake button is stuck or damaged, it could be continuously triggered which prompts the iPhone to emit a siren sound and not turn on properly (1). Trying to hard reset with the volume and power buttons won’t work if the power button itself is not functioning. The siren noise indicates the phone recognizes the faulty input.
Damaged proximity/ambient light sensor – The proximity sensor detects when your face is close to the screen. If this is faulty, it could cause the screen to stay black and emit a siren during startup as the phone believes it is still in a call or pocket (2).
Faulty audio IC chip – The audio IC chip controls many aspects of sound on the iPhone. If it is damaged, it could improperly trigger the siren sound when powering on or off the device (3).
In any hardware failure case like the above, the iPhone needs to be examined and repaired by an Apple technician. A siren at startup likely indicates a key component is damaged and preventing normal function.
Sources:
(1) https://discussions.apple.com/thread/8436308
(2) https://discussions.apple.com/thread/253380872
(3) https://discussions.apple.com/thread/254422330
Stuck Power Button
A stuck or faulty power button is one of the most common reasons an iPhone may start making a loud siren noise when trying to turn it on or off. This is because the phone interprets rapid presses of the power button as an emergency input.
The power button on an iPhone serves several purposes – turning the device on or off, locking the screen, activating Siri, and triggering Apple Pay. If the button gets stuck in a pressed-in position, it can essentially send repeated power off signals to the iPhone.
In response, the iPhone will initiate a shutdown process. Part of this involves sounding a loud emergency-style siren alert before powering down. This alarming sound occurs because the phone thinks something is wrong based on the constant power button input.
A stuck power button is usually caused by a hardware problem, such as dirt or debris getting lodged in the switch mechanism. It may also be due to physical damage if the phone was dropped. In some cases, moisture can gum up the works and lead to the button sticking.
If an iPhone begins blaring a siren every time you try to turn it on, a stuck power button is likely the culprit. The siren will sound for several seconds before the phone force shuts down.
The only solutions are to try cleaning around the button or to have the phone repaired so the power button can function normally again. Simply locking the phone and using on-screen buttons to turn the display off can act as a temporary workaround.
Software Glitch
In some cases, an iPhone making a siren noise may be caused by a software glitch. This seems to be more common following an iOS update. For example, some users have reported alarm issues after updating to iOS 12.4 (source). One workaround is to delete all alarms from the Clock app, restart the device, and recreate the alarms. However, the underlying bug may still persist.
There are also reports following iOS updates of iPhones making siren noises and displaying black screens, rendering them unusable (source). This points to system errors that can cause false siren alerts. Restarting the device or performing a factory reset may resolve isolated software glitches. But recurring issues likely require an iOS patch or update from Apple to fully fix.
In summary, while rare, bugs introduced in iOS updates can trigger false siren noises. Users typically notice this soon after updating. Until Apple addresses the root causes, workarounds like rebooting or removing alarms provide temporary relief. But the only definitive solution is installing the necessary software fixes as they become available.
Conclusion
The main reasons that an iPhone might make a loud siren noise can usually be narrowed down to a few key culprits. One of the most common reasons is the iPhone receiving an emergency alert or Amber Alert through its notification system. These alerts are designed to be attention-grabbing in order to notify users of imminent dangers or missing children. Another possibility is that a timer or alarm that was set on the iPhone has expired and is buzzing to alert you. Critical battery alerts and the sound the iPhone makes when powering down can also sometimes sound similar to a siren.
Hardware issues like a stuck power button or a software glitch can also cause an iPhone to unexpectedly blare a siren-like noise. If the sound persists, restarting the iPhone or performing a reset of the device can often resolve software-related causes. For hardware problems like a jammed power button, taking the phone to an Apple Store for examination and possible repair may be necessary. With some basic troubleshooting, users can typically get to the bottom of an iPhone siren sound and restore normal operation.