Somtimes phone's speaker not work properly because stuck dust or water inside speaker and sound coming from phone speaker is muffled. So you need to clean speaker and eject water or dust from speaker.

Improve sound quality by using fix my speaker dust and water ejector tools.
Repair broker sound and improve speaker sound quality with fix my speaker volume.

Within a second, user can fix the speaker audio by playing ultra sound wawe.

Speaker cleaning tools has a some predefined sound frequencies to help boost volume.