Audio Recording Techniques
We are here to help you meet the challenges of recording birds and other animals in the wild. This page contains suggestions about how to maximize the quality of your audio recordings, then you can get going editing and uploading your recordings using eBird. Also check out our informational videos at the bottom of the page.
Check that your gear is functioning properly before taking it into the field. Be sure you know how it works, and you feel comfortable setting it up and using it. This will reduce the chance that you will miss a great recording opportunity and increase the chance that you will capture a great recording. The more comfortable you are with your equipment, the more enjoyable your experience and the better your recordings. WAV is the standard audio format used at the Macaulay Library, the Library of Congress, and other sound archives dedicated to the long-term preservation of audio. WAV is an uncompressed audio format that provides an accurate copy of wildlife sounds. By recording in the WAV format, you will maximize the usefulness of your recordings for research and conservation both today and in the future. Learn more.
If you recorder supports it, a sample rate of at least 48 kHz and a bit depth of 24 bits is also recommended.
Getting closer drastically increases the volume of your target compared to the background. Cutting your distance in half will double the perceived loudness of the desired signal. So move closer, but do so slowly and quietly to be careful to not disturb your subject. Position the microphone to minimize obstructions between it and the vocalizing animal. When using a directional microphone, aim it directly at the subject. This is especially important when using a parabolic microphone system, given its extreme directionality. Adjust your position to reduce interfering noise: have your back to unwanted noise with the parabola, and have the noise to the side with a shotgun microphone. Proper aim will increase the quality of the recording of your subject, while reducing the interference of background noise. If your recorded sound is louder than your recorder’s maximum level (0dB on the recorder’s meter), you will introduce distortion into your recording. To avoid this, set your record level so that the loudest part of the target vocalization peaks at a safe level (such as -12dB), then leave it there unless the target gets louder and you risk hitting 0dB.
Recording at a safe level (left); distortion occurring (right)
Set the record level for each recording segment and leave it at that setting until your next new recording segment. Changing the record level during a recording results in an uneven
sound that affects the quality of the recording.
The most valuable recordings are ones that capture a number of different calls or songs or capture the variation of calls and songs. If you are in a good situation, it is worth recording for several minutes. However, also consider whether you have the opportunity to get closer or otherwise take action to obtain a better recording. If so, you may wish to end your first recording after a few minutes and try for a better opportunity. The better the quality of the recording, the more worthwhile it is to keep going; the longer you record, the more likely it is that your subject will do something interesting! Microphones are sensitive and will pick up everything around them. Everyday sounds like traffic, airplanes, and moving water can be tuned out by our brains, but manifest themselves as unwanted background noise in recordings. If you can find an area where these noises are less prominent, it will be much easier to obtain a clean recording. Use a windscreen to reduce the impact that gusts of wind have on your recordings.
It is also important to remember that microphones pick up sounds close to them better than distant birds, and nothing is as close to the microphone as YOU. Be aware of the sounds you or your companions make. Try not to move, walk, talk, or otherwise make noise during a recording, and ask any companions with you to do the same. Minimize handling noise by being careful about how you hold your microphone or recording device. Using a shock mount for a microphone will also reduce these unwanted bumps and clicks. Finally, keeping yourself quiet is easier when you wear “quiet” clothing like fleece, wool, or cotton, rather than noisier clothing like a raincoat.
It’s easy to lose track of exactly what happened during a particular recording, particularly hours, day, or even longer, later. Making a voice announcement at the end of each recording can help you and others figure out what was going on and capture important contextual information that may be relevant to the sound the bird was making. Describe basic information, such as the species, date, time, and location. Perhaps just as importantly, it is useful to describe the behavior of the bird. Where was it when you recorded it? What was it doing? Was it moving around or on a perch? Were there other individuals or species that made sounds in the recording or may have influenced the vocalizations of your subject? Anything you can say about what was going on is valuable information. You can also provide the habitat or weather and any other relevant information, such as the equipment being used or the recordist’s name, especially if equipment is being shared between more than one person. You put in a lot of hard work to get your recordings, so don’t lose your efforts. Keep your files and records organized and ready to upload to eBird. The sooner you can organize your files and get them archived at the Macaulay Library, the less likely it is that any data will be lost.