This is likely produced by the electrical power supplied to the computer. This problem can be solved when you:
- Disconnect the computer from power and run it on battery when recording.
- Disconnect the computer from other things that might be connected to power, such as a projector.
- Disconnect the computer from any cables, such as a network cable for internet.
Many things can cause background noise such as people talking, motorbikes outside, or a fan in the room. Try these things to reduce background noise:
- Use a high-quality microphone. Check your Window’s Sound settings to be sure this microphone (and not the computer’s internal microphone) is selected as your default Input/Recording device.
- Record in a room that has minimal noise. If there are windows, make sure they are closed when recording. It will also help to add rugs, blankets, or mattresses on the windows, doors, and walls.
- Turn off any aircon units and fans when recording. If air-con is needed keep it on a low fan speed while recording. Prevent air from blowing towards the face or microphone.
- Avoid using fluorescent lights as this can cause a buzz in the recording.
Wind Noise and Popping/Plosives
Wind noise can be created by the recorder’s breathing or touching the microphone. Popping or plosives happen when saying words that start with letters like “p” which can create wind noise in the recording. To fix this issue:
- Refer to the section below titled “How to wear a headset microphone.”
- Use a ‘windscreen’ like the black foam windscreen covering the microphone in the picture below.
- Ensure that the microphone is not directly in front of the mouth as pictured below.
This is often referred to as the speaker’s “presence” in a recording. If a speaker does not have good presence, they sound far away and distant. This can be improved by:
- Moving the microphone closer to the mouth (but not directly in front of the mouth) as pictured below. If using a microphone that sits on a table, the speaker should be this distance from the microphone: 10cm (4") for softer voices up to 15cm (6") for louder voices.
- If the microphone boom is not flexible and this mic position results in wind noise from the mouth or nose, then place the mic at the level of the nose, out of the airflow, and increase the recording volume.
The best way to adjust your recording levels is through Sound Settings in Windows. Open Sound Settings\Input (make sure your high-quality microphone is selected)\Device properties\Volume
- Too low: In Render, the voice waveform can be too small. Increase the Windows recording (input) volume until the waveform is larger, filling more of the Render recording window.
- Too high: In Render, the voice waveform can be too big, reaching the top and bottom limits. Decrease the Windows recording (input) volume until the waveform is smaller, filling the Render recording window without touching the top and bottom limits a lot (in a few places is OK).
This problem occurs when the recorder’s voice reflects off of walls, windows, the floor, the ceiling, and any hard surfaces in the room. This can be solved by:
- Soften all hard surfaces by adding carpets on the floor, hanging comforters or blankets on the walls, and surrounding the recording table with mattresses.
- Reduce the recording volume and locate the mic at the level of the mouth but not in front (see photo below). If it is a tabletop mic, move the person closer to the mic when recording and make sure they are speaking into the correct side of the mic.
- See the section below titled “How to set up a room for recording.”
Automatic, uncontrolled volume fluctuations: Please check to see if Automatic Gain Control (AGC) exists in the Windows settings for the microphone you are using.
- With the right button on your mouse, click the speaker icon in the system tray on the bottom right of the screen.
- Choose “Open sound settings.”
- Under “Input” choose your microphone. Then click the blue link “Device properties.”
- Click “Additional device properties" on the far right of the screen.
- In this Window, AGC will be on a tab called "Custom" if it exists. (Some microphones do not have this tab because they do not have AGC.)
- If you do have a custom tab, make sure AGC does not have a checkmark in the box next to AGC. Like this:
How to wear a headset microphone
The microphone on the headset should be placed in front of the face. Do not put the microphone directly in front of the mouth as this can cause popping in the recording. Rather, place it somewhere to the side or below the mouth.
How to set up a room for recording
A room with hard walls and floors will lead to poor audio quality. To fix this, use local supplies such as blankets, rugs, cushions, and mattresses to add more padding to the walls and floors where the translation teams are working and recording. Adding soft furniture (such as couches or chairs) will also help, if available. Each translation team will need their own space to record, so be sure to get enough for both rooms.
Here is an example of rooms with a cement floor and walls. In this project, mattresses and foam were added to the walls and blankets were hung up with string to surround the translation team’s table. When they are not recording, they can open the blankets so it does not get too hot.
Use the supplies that you have available to cover hard surfaces in the rooms where the translators are working. This will reduce echo and create a much better recording. You can always email firstname.lastname@example.org and ask them to check your audio quality or to ask how you might improve your audio quality. In your email be sure to include the set number(s) you want checked and any pictures of your current recording room setup.