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If I'm understanding correctly, the speaker function on your iPhone is not working since updating the iOS. I know how important it is to have the use of the speaker, and I'll be happy to help.
Check out the steps below to see if it helps from our article: If you hear no sound or distorted sound from your iPhone, iPad, or iPod touch speaker
Check sound with an app
Open an app that has music or sound effects, then adjust the volume with your volume buttons or the slider in Control Center.
Plug headphones into your device
If you can hear sound through the headphones but not through your device's speakers, unplug the headphones and clear dust or debris from the headset port on your device.
Turn off Bluetooth
To make sure that your device isn't sending audio to a Bluetooth accessory, go to Settings > Bluetooth and turn off Bluetooth.
Restart your device