Troubleshooting

Refer to the following steps to allow microphone access permissions

On Mobile

From Postman Calls App Settings

1. Tap and hold the Postman Calls app icon

2. Click on "Site settings"

3. Under "Permissions", toggle to allow Microphone access

4. Close and relaunch the Postman Calls app

From Browser App Settings

1. Access your browser's app settings. There are two main ways to do so:

   1. Tap and hold your browser icon, and tap on the information ℹ️ icon in the sub-menu

   2. In your phone settings, Apps > Google Chrome

2. Select Permissions > Microphone > Allow only while using the app

3. Close and relaunch the Postman Calls app

If needed, you may also uninstall and reinstall the Postman Calls app before allowing the microphone access permissions again.

On Desktop

1. Access your browser's settings via the menu (three dots at the top right corner)

1. Select Privacy and Security > Site Settings > Recent Activity > postman-calls.gov.sg

1. Set Microphone to Allow

1. Refresh the page and try again

2. If needed, close all browser tabs to restart your browser before trying again.

Quick Check: use the in-call volume indicators

On the call screen, Postman Calls shows two audio indicators:

• Your volume (red): how much of your voice the app is detecting and sending.

• Recipient volume (blue): how much incoming audio the app is receiving from the recipient.

In a normal conversation:

• Your volume should show green activity when you speak.

• Recipient volume should show green activity when the recipient speaks.

If you cannot hear the recipient, and

1. Recipient volume is non-zero (i.e., shows activity)

   1. This is means Postman Calls is receiving audio, and that the issue is likely with your device or audio output.

   2. Try the following:

      1. Confirm that your preferred audio output device is selected on the call screen

      2. Confirm that your preferred audio output device is connected

         1. Disconnect and reconnect your audio device (if applicable)

         2. After which, re-select it as the audio output

      3. Increase your device volume

         1. Ensure that the volume setting configured corresponds to your preferred audio output device

         2. [Android] Depending on the devices connected and selected, the volume settings should be configured accordingly

      4. Switch audio output

         1. [Mobile] On the call screen, toggle the audio output between available options (e.g., speakerphone, headset earpiece, bluetooth headset, usb audio)

         2. [Desktop] On the call screen, toggle your Speaker device between the available options (e.g., built-in speakers, wired/wireless earpiece)

2. Recipient volume is zero (i.e., shows no activity)

   1. This means that Postman Calls is not receiving incoming audio. The cause is likely on the recipient side, though network conditions on either end can contribute.

   2. Common causes include:

      1. The recipient is muted or speaking too softly for their microphone to pick up.

      2. The recipient’s microphone is not working (hardware issue, permissions, or headset problem).

      3. The recipient has poor network connection, causing audio dropouts.

      4. In some cases, poor network on your side can also prevent incoming audio from coming through reliably.

   3. Try the following:

      1. Wait briefly: give it a few seconds to see if the issue resolves (especially if either party is moving between network areas).

      2. Confirm with the recipient (if possible): ask if they are muted or using a headset with a faulty microphone.

      3. End the call and retry. If you suspect connectivity issues, switch to a more stable connection before retrying.

      4. Redial after a short pause: wait 5–10 seconds, then redial. This can help if the recipient’s network or device is temporarily stalled.

3. You have navigated away from the app (on mobile)

   1. If you leave the Postman Calls app during an active call, the app may temporarily lose access to your phone’s microphone and audio session

   2. What to do

      • Return to Postman Calls immediately. In many cases, audio will recover once the app is back in the foreground.

      • If you were away for longer and the call ends, this is expected behaviour. Simply redial the recipient and continue the call.

   3. To avoid this issue, keep Postman Calls open and in the foreground for the full duration of the call.

Quick Check: use the in-call volume indicators

On the call screen, Postman Calls shows two audio indicators:

• Your volume (red): how much of your voice the app is detecting and sending.

• Recipient volume (blue): how much incoming audio the app is receiving from the recipient.

In a normal conversation:

• Your volume should show green activity when you speak.

• Recipient volume should show green activity when the recipient speaks.

If your recipient cannot hear you, and

1. Your volume level is non-zero (i.e., shows activity)

   1. This is means Postman Calls is receiving your audio, and that the issue is likely with the recipient's device, though network conditions on either end can contribute.

   2. Common causes include:

      1. The recipient's audio output volume is too low.

      2. The recipient’s audio output device is not working (hardware issue, permissions, etc).

      3. The recipient has poor network connection, causing audio dropouts.

      4. In some cases, poor network on your side can also prevent outgoing audio from coming through reliably.

   3. Try the following:

      1. Wait briefly: give it a few seconds to see if the issue resolves (especially if either party is moving between network areas).

      2. End the call and retry. If you suspect connectivity issues, switch to a more stable connection before retrying.

      3. Redial after a short pause: wait 5–10 seconds, then redial. This can help if the recipient’s network or device is temporarily stalled.

2. Your volume level is zero (i.e., shows no activity)

   1. This means that Postman Calls is not receiving incoming audio. The cause is likely with your device microphone.

   2. Try the following:

      1. Confirm that your preferred audio device is selected on the call screen

      2. Confirm that your preferred audio device is connected to your device

         1. Disconnect and reconnect your audio device (if applicable)

         2. After which, re-select it as the audio output

      3. Switch audio devices

         1. [Mobile] On the call screen, toggle the audio device between available options (e.g., speakerphone, headset earpiece, bluetooth headset, usb audio)

         2. [Desktop] On the call screen, toggle your microphone device between the available options (e.g., built-in microphone, wired/wireless earpiece)

      4. Avoid switching between Bluetooth devices mid-call

3. You have navigated away from the app (on mobile)

   1. If you leave the Postman Calls app during an active call, the app may temporarily lose access to your phone’s microphone and audio session

   2. What to do

      • Return to Postman Calls immediately. In many cases, audio will recover once the app is back in the foreground.

      • If you were away for longer and the call ends, this is expected behaviour. Simply redial the recipient and continue the call.

   3. To avoid this issue, keep Postman Calls open and in the foreground for the full duration of the call.

Common Causes

• Unstable internet connection: weak signal, network congestion, or switching between Wi-Fi and mobile data mid-call can interrupt the call.

For mobile users specifically:

• Leaving the app during the call: navigating away from the app or locking your phone screen may cause the call to terminate

• Accidental hang-up: because the screen may not dim/lock like a native dialler, your cheek/face can tap the on-screen hang-up button.

• Power saving measures: battery saver or background restrictions can interfere with Postman Calls during long calls.

• External call interruptions: an incoming cellular call or certain system prompts/overlays may interrupt the call session.

Potential Fixes

1. Check your connection

   • Move to a location with better signal.

   • If you suspect Wi-Fi instability, try switching to mobile data (or vice versa) before redialling.

   • Avoid switching networks mid-call where possible.

2. Retry the call

For mobile users specifically:

1. Stay in the app during the call

   • Keep Postman Calls in the foreground during the entire call.

   • Avoid switching apps or multitasking until the call ends.

2. Keep your screen on

   • Do not lock your phone screen during the call.

3. Avoid accidental screen touches

   1. Avoid placing your cheek/face directly on the screen.

   2. Consider using speakerphone or a headset for longer calls.

Try the following:

• Restart the app and retry login

• Switch login method (Singpass ↔ Email OTP)

1. Tap the Recents icon

2. Close the Postman Calls app by Swiping Up or tapping “Close all”

3. Tap on the Postman Calls icon again to re-enter the app

Uninstallation Steps:

1. On your apps screen, tap and hold on the Postman Calls icon and tap “Uninstall”

2. Tap “OK” to confirm uninstallation

Installation Steps:

1. Tap the menu button (three dots) in Google Chrome

2. Tap "Add to Home screen"

3. Confirm installation