Internal Speaker
i don’t see Internal Speakers as an option in the Output window it's only when the computer star i can heard the song after that if i play a music not working. and can't heard anything what should I do..
MacBook Pro 15", macOS 10.14
Go step by step and test.
1. System Preference > Sound > Output > Internal Speakers, if it is listed.
Highlight Internal Speakers.
Make sure that Mute is not enabled.
2. Plug in and remove the headphone.
If you see red light in the headphone port, plug the headphone
in and out of the port 5 or 6 times to flip the microswitch inside.
Sound output may be stuck in digital mode.
3. Reset PRAM. http://support.apple.com/kb/PH18761
4. Reset SMC. https://support.apple.com/en-us/HT201295
5. Try starting up in Safe Mode. https://support.apple.com/en-us/HT201262
Once in Safe Mode, click the “Restart” button at the bottom.
5. Applications > Utilities > Audio MIDI Setup
Audio Devices window > Side Bar
Click the Built-in Output.
Make sure that box is not checked under “Mute”.
Make sure that Format is set at 44,100.0 Hz.
Right click on the Built-in Output for available options.
Click the Gear icon and click “ Use This Device for Sound Output”