4412D+ Have 4412D+, When receiving calls, users weren't able to hear callers from the handsets or the speaker phone. phone system is an IP Office 406 DS 406 version 4.1(12).

To be check handset speakerphone part or electronic part for that speakerphone. There is difference handset speakerphone and speaker.

it's something dust in the microphone

Make sure the Plantronics S11 headset is plugged into your handset jack on your phone, not the headset jack, this will make a difference on most phones. After plugging the S11 into the handset jack on your phone, you will need to pick up your handset receiver and sit it off to the side of the phone to place a call or to receive a call, after you are finished with your call sit the handset receiver back in the cradle on your phone.

Good luck from Headsets Direct!

Is this an IP Office?
This is how it works. For some reason the IP Office waits for teh first 2 rings to get caller ID, and then lets the call ring in.

Activating Personal Ring
You can assign special ringer tones to anyone in your phonebook. When your phone gets a call, it looks up the Caller ID information in your phonebook. If you've assigned a personal ringer to that number, the phone uses it so you know who is calling. To turn the personal ringing on or off, follow these steps:

1. Press [Menu/Select]. Select the HANDSET SETUP menu, and then the PERSONAL RING submenu.
2. Move the cursor to select ON or OFF.
3. Press [Menu/Select]. You will hear a confirmation tone.

Selecting a Ring Tone (Handset only)
You may choose from four melodies or three tones for your phone's primary ring tone. Each handset can use a different ring tone or melody. The available ring tones are as listed:

1. Press [Menu/Select]. Select the HANDSET SETUP menu, and then the RINGER TONES submenu.
2. Move the cursor to select a ring tone. As each ring tone is highlighted, you will hear a sample.
3. When you hear the tone you want to use, press [Menu/Select]. You will hear a confirmation tone.

Adjusting the Speaker Volume
Handset Speakerphone: You can choose from six volume levels for the handset speakerphone. To adjust the speaker volume while on a speakerphone call, press the UP Arrow button (to make it louder) or the Down Arrow button (to make it softer).
Base Speaker: You can choose from ten volume levels for the base speaker. To adjust the speaker volume while call screening or playing messages, press [volume +] (to make it louder) or [volume -] (to make it softer).

Adjusting the Audio Tone
If you aren't satisfied with the audio quality of your phone, you can adjust the Audio Tone of the earpiece while on a call. Your phone gives you three audio tone options: low, natural and high; the default setting, Natural Tone, is recommended for hearing aid users. Audio tone adjustments only apply to the earpiece, not the speakerphone.
To adjust the audio tone:

1. While on a call, press [Menu/Select].
2. Move the cursor to select AUDIO TONE, and then press [Menu/Select].
3. Move the cursor to select desired option (HIGH TONE, NATURAL TONE, or LOW TONE), and then press [Menu/Select]. Selected option appears in the display for two seconds, and then the display returns to normal.

Deleting Phonebook Entries
You can delete a single phonebook entry at a time or all phonebook entries at once:
To delete a single phonebook entry:

1. When the phone is in standby, press the phonebook key.
2. Find the entry that you want to delete and press [Menu/Select].
3. Select DELETE. DELETE ENTRY? appears in the display.
4. Move the cursor to select YES.
5. Press [Menu/Select]. You will hear a confirmation tone, and DELETED! appears in the display.

Deleting Caller ID Numbers

1. To delete only one Caller ID number, press the Caller ID button when the phone is in standby, and then find the number you want to delete.
2. Press [Menu/Select] and select DELETE ENTRY.
3. When the phone asks you to confirm, select YES.

1. To delete all the Caller ID numbers, press the Caller ID button when the phone is in standby, and then press [Menu/Select].
2. When the phone asks you to confirm, select YES.

Note: When you delete a Caller ID number, you delete it permanently.

Deleting a Redial Record
If you want to delete a phone number from the handset's redial list, follow the steps below:

1. When the phone is in standby, press [Redial/Pause].
2. Use the UP Arrow button and the Down Arrow button to scroll through the redial list.
3. When you find the redial number you want to delete, press [Menu/Select] and select DELETE ENTRY.
4. When the phone asks you to confirm, select YES. The redial number is deleted.

Resetting the Voice Message Waiting Indicator

1. When you receive a new voice mail message, the new message LED on the top of the handset flashes and VM appears in the handset display.
2. In the event your message alert tone gets out of sync with your phone company's voice messaging system, you can reset back to its original "no messages waiting" state.
3. To reset, press and hold [find hs] on the base for five seconds.
4. A beep sounds and the message alert tone is reset.

I’m happy to help further over the phone at https://www.6ya.com/expert/jeremy_69f3cc28d95bf514

Which system is this on? Could be Merlin Magix or Avaya IP Office.

Are you using speaker phone? Are you using the Hand Set?

If you are using the speaker phone, the first thing is to check the back end configuration of your IP phone system and Make sure that that Station has the Microphone Feature enabled. If it does, then the next step would be to configure a different phone with your same extension and ip. If that phone works fine, then it tells you that it is the microphone inside the original phone that is bad.

If it doesn't fix it, then the problem lies on some of the settings within your phone system.

Some other simply things to try if using the Handset, is 1) Replace the cord from the telephone base to the handset. 2) Grab a similar headset and hook it up to your phone. Test calling someone internally in the office, and out of the office.

go to the setting on the handset -> advanced-> reset
I think the default pin is 0000
It will restart. I had the same problem And find the solution somewhere else
I worked for mine
Good luck

It sounds like you have a defective handset cord or handset. First, at your phone, switch your handset with another phones handset that you know for sure works. From your phone make a test call. If the caller can now hear you, the original handset from your phone is defective. If the caller still can not hear you, switch your handset cord with another handset cord from another phone that you know works. From your phone make another test call. If the caller can hear you, then your original handset cord is defective. You can purchase another handset cord from your local office supply store. Your phone uses a standard handset cord. It may be difficult to match the original color of your handset cord. Be sure to take your defective handset cord with you, so you can try to match the color. If the caller still does not hear you. Put your original handset and original handset cord back on your phone. Then plug your phone in to another wall jack, that you know works with another phone. The other phone needs to be an identical phone to yours (same number of buttons and same model number. The model number can be found under the phone). Wait approximately 90 seconds, sometimes longer, after you plug your phone into the other wall jack. Now, make another test call from your phone. If the caller can now hear you from your phone with it plugged into another working jack, then you have a defective station port or jack where your phone was originally plugged in at. If the caller still can not hear then you have a defective phone.