Your phone defaults to speakerphone during calls because of an audio routing setting, a connected Bluetooth device, or a paired wearable that’s redirecting where the sound goes. In most cases, a single setting change fixes it. The exact cause depends on whether you’re using an iPhone or Android, and whether you have accessories like a smartwatch or hearing aids connected.
Call Audio Routing on iPhone
The most common culprit on iPhones is a feature called Call Audio Routing, buried in the Accessibility settings. This controls where your call audio goes by default, and if it’s set to “Speaker,” every incoming and outgoing call will start on speakerphone without you tapping anything.
To check this, go to Settings > Accessibility > Touch > Call Audio Routing. You’ll see options for Automatic, Bluetooth Headset, or Speaker. If “Speaker” is selected, switch it to “Automatic.” This tells your iPhone to route audio to the earpiece unless a Bluetooth device is connected, in which case it sends audio there instead.
This setting is easy to toggle accidentally, especially if you’ve been exploring Accessibility options or if a software update reset your preferences. It’s also worth noting that the same menu contains an Auto-Answer Calls toggle. If that’s turned on, your phone will pick up incoming calls after a set number of seconds without you doing anything. Combined with the Speaker routing option, this can make it seem like your phone has a mind of its own.
Bluetooth Devices and Smartwatches
A connected Bluetooth device can override your phone’s default audio behavior in unexpected ways. If you answer a call while Bluetooth headphones or a car stereo are paired but not physically in use (headphones in a bag, for instance), the audio may route to the speaker as a fallback because your phone detects the Bluetooth connection is active but can’t actually deliver sound through it.
Smartwatches add another layer of confusion. If you have an Apple Watch or Galaxy Watch paired to your phone, the call audio routes to whichever device you answer on. So if a call rings on both your phone and your watch, and you pick up on the phone, the audio stays on the phone’s earpiece. But some users report that answering on the phone while a watch is actively connected sends audio to the watch’s tiny speaker instead, which can sound like the call is on speakerphone or playing out loud. On Galaxy Watch models, this behavior varies: some route audio exclusively to whichever device picks up, while others default to the watch if Bluetooth is active.
The fix is straightforward. If you don’t want your watch handling calls, disable the phone call feature in your watch’s companion app. On Apple Watch, open the Watch app on your iPhone and adjust the call settings under Phone. On Samsung, use the Galaxy Wearable app to control how calls are routed.
Hearing Aids and Accessibility Devices
If you use Made for iPhone (MFi) hearing aids or other accessibility audio devices, your phone may automatically route call audio to those devices. Apple allows you to choose whether phone and media audio go to a paired hearing device, and this routing happens automatically once the devices are paired. If your hearing aids are off, out of range, or low on battery, the phone may fall back to speakerphone rather than the earpiece.
You can manage this in Settings > Accessibility > Hearing Devices on iPhone. If you’ve paired hearing aids with multiple Apple devices (like both an iPhone and an iPad), the audio connection switches automatically between them based on which one is generating sound. This can occasionally cause routing conflicts during calls.
Third-Party Apps That Change Call Behavior
Apps like Zoom, WhatsApp, and other VoIP services handle call audio independently from your phone’s built-in dialer. Each app has its own audio routing logic, and some default to speakerphone for video calls or conference calls. Zoom, for example, has been reported to auto-answer calls when a Bluetooth headset is connected, because the app interprets the Bluetooth connection as a signal to pick up. In at least one documented case, a completely unrelated app (a game-enhancement tool) interfered with Zoom’s call notification system.
If the speakerphone issue only happens in a specific app, check that app’s settings first. Most VoIP apps have an audio output option within their in-call interface or settings menu. Also check whether the app has permission to access your phone’s Bluetooth, as this can trigger unexpected routing behavior.
Software Bugs After Updates
Major operating system updates occasionally introduce audio bugs. After iOS 18 rolled out, multiple users reported degraded call quality and unusual audio behavior, including problems with speakerphone calls over Wi-Fi and cellular data. These issues typically stem from changes in how the OS manages audio streams and are resolved in subsequent point updates.
If your speakerphone issue started right after an update, check whether a newer version is available. You can also try resetting your network settings (Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings), which clears saved Bluetooth pairings and Wi-Fi connections and can resolve audio routing glitches. You’ll need to re-pair your Bluetooth devices afterward.
Quick Fixes for Android
Android handles call audio routing differently depending on the manufacturer. On Samsung devices, check Settings > Accessibility > Answering and Ending Calls, where you’ll find options that may auto-answer or route to speakerphone. On Google Pixel phones, open the Phone app, tap the three-dot menu, go to Settings > Sounds and Vibration, and look for any speaker-related toggles.
If you’re using Android with a Bluetooth device that keeps activating speakerphone, go to Settings > Connected Devices and check whether any paired device has a phone audio profile enabled. Disabling the phone audio profile for a device (while keeping media audio active) prevents it from interfering with calls while still letting you listen to music through it.