How do i get volume on my binatone 3325 handset

Press C/8 to unmute the microphone.

complete installations
Plug the power adapter
& line cord
into the base station.
Plug the power adapter into a 230Vac, 50Hz
mains socket, the other end of the line cord
into your telephone line socket.
Warning: Always use the line cord provided in the box.
Other line cords may not be compatible and may not work.
Warning: Only use the power adapter supplied.
Others will result in non-compliance with the safety
specification EN60950, and will invalidate any approval
given with this apparatus.
Warning: The Base unit needs mains power for
normal operation, not just for charging the handset batteries.
Installing and charging the batteries
Slide open the battery compartment cover.
Place the 2 batteries with the correct polarity,
as shown.
Slide the battery compartment cover back.
Put the handset on the base and charge for
15 hours before first time use. The handset
beeps when charging starts.
Warning: Only use the AAA size NiMH rechargeable
batteries.
If you have a Broadband Line
If you connect your telephone to a line with a broadband connection, you will need to
insert a micro-filter between the telephone and the telephone line, otherwise you may
get interference between the telephone and the broadband, which could cause
problems.
In a home with broadband, every telephone must have a micro-filter connected, not just the one at the telephone point that your modem is connected to.
If you need more broadband micro-filters, contact your broadband provider.

Connection and Conditions for use:
You can connect your phone to a direct exchange line (DEL) on a local
exchange with its own phone number; to an extension socket
connected to a DEL; or to an extension on an approved compatible
PBX. Do not connect as an extension to a payphone.
The ringer equivalence number (REN) of all equipment (phones, fax
machines, modems, etc.) connected to an exchange line must not add
up to more than 4, otherwise one or more of them may not ring and/or
answer calls correctly. This phone has a REN of 1, and most other
telephones have a REN of 1 unless marked otherwise.
Handset - Base Connection
1) When purchased, all handsets are already registered to the base unit
and should link to it when they are all powered up.
2) To use your cordless handset and base unit together, you must be
able to establish a radio link between them. The signal between the
handset and the base is in accordance with the normal standards for
a DECT phone: Maximum range up to 300 metres outdoors or 50
metres indoors. Be aware that:
> Any large metal object, such as a refrigerator, mirror or filing cabinet,
between the handset and the base unit may block the radio signal.
> Other solid structures, like walls, may reduce the signal strength.
> Other electrical equipment may cause interference and/or affect the range.
3) Do not place close to another telephone, a TV or audio equipment - it
may cause interference.
4) Out of Range warning. If you hear a warning tone during a call,
and/or the sound in the earpiece becomes faint or distorted, you may be
going out of range of the base unit, so move nearer to the base unit
within 20 seconds, otherwise the call may be cut off.