A front-facing speaker fires toward you rather than out of the bottom edge. That changes both what accumulates in it and how you can safely clean it.
For a complete overview, see earpiece-specific cleaning.
Where they actually are
Front-firing designs place the driver behind a slot in the bezel above or below the screen. On most
current phones the top slot doubles as the earpiece and the second stereo channel. On older phones with
larger bezels, and on some gaming phones, there are genuine dedicated front-firing speakers at both
ends.
Identifying yours
Play a mono voice memo and cover each opening in turn with a fingertip. Whichever ones change the
sound are real outputs. This matters because many phones include a decorative grille that produces
nothing — present purely for visual symmetry — and people spend effort cleaning an opening that was
never a speaker.
Different debris from a bottom speaker
Front slots face your face rather than your pocket, so they collect facial oil, makeup, sweat and
hair rather than textile lint. That residue is sticky rather than loose, which changes the method: it
responds to adhesive putty and brushing far better than to acoustic cycles.
Screen protectors are a frequent cause
A protector cut slightly wrong, or applied a millimetre off-centre, will partially cover a front
slot. The result sounds exactly like a blockage. Check this before anything else — it accounts for a
meaningful share of "front speaker suddenly quiet" reports on otherwise healthy phones.
Cleaning constraints
Front slots sit close to the display and, in the top position, close to the proximity sensor and
front camera. That rules out anything wet, anything sharp, and compressed air. Adhesive putty pressed
lightly and lifted straight off is the safest effective method; a soft dry brush along the slot helps
with loose surface material.
If acoustic cycles are used
Lower volume than the main speaker, because the driver is smaller. Two cycles is a reasonable
limit — sticky residue will not respond to more.
The proximity sensor side effect
Because the sensor often shares the top slot area, the same film that muffles audio can cause the
screen to stay awake during calls or register cheek touches. Cleaning frequently resolves both, which
is worth knowing before assuming two separate faults.