Noise Reduction For Your Audio Recorder
Hums, clicks, rustles and chirps are some of the audio elements that can spoil your recordings. Using noise reduction techniques like noise gating, frequency cutoffs and equalization can reduce these unwanted sounds without sacrificing voice clarity.
Keeping your signal path short is important. All electrical circuitry adds a little noise, so the less there is between source and destination, the better.
Background noise is a common problem in audio recording and can be difficult to eliminate. It can affect the clarity of a voice or music and reduce the overall quality of an audio file. Often, it is caused by environmental factors such as wind, traffic, or even a fan in the room. In addition, ambient noise can be caused by the microphone or other audio equipment.
Using software can help to remove background noise from your recordings. It can also boost the recording volume and provide a wide range of audio editing features. In addition, it can help to avoid unwanted noises such as clicking and hissing during recordings.
It is important to know that noise reduction is always a trade-off between the amount of noise removed and the quality of the remaining audio. Consequently, the best results are achieved when the background noise level is low. A higher background noise level can cause bubbly metallic artifacts to appear in the sound.
The sudden and brief sound of gunfire or explosions, a jackhammer at work, fingernails scratching on chalk bulletin board, squealing brakes or any other sharp, alarming noise generates impulse noise. These sounds can be damaging because they reach your inner ears without attenuation. Even a single blast that lasts less than a second can cause hearing loss.
Impulse noise and impact noise are different from continuous sound waves in that they have a much shorter peak amplitude. They can also be characterized by a rapid rise time. These characteristics make them challenging to measure.
Impulse noise requires a recording system with demanding technical specifications including an extremely fast rise time (optimally, less than 10 microseconds to peak); a wide dynamic range; a high maximum sound pressure level; and a fast response. Existing damage-risk criteria based on peak level, duration and number of impulses are difficult to apply to impulse noise. A new damage-risk criterion based on Leq, the equivalent continuous A-weighted sound level, may provide a more appropriate approach.
It’s not always necessary to use high-tech noise reduction for microphones — sometimes the best solution is to avoid it altogether. That means finding the quietest room or environment to work, and getting familiar with the ambient sounds of that place — for example, traffic, neighbors, birds, heating and cooling systems. If possible, try to record at night or early morning when things are usually quieter.
Irregular and impulsive noises are much harder to reduce than continuous background noise. These are the sounds that can jar our ears and make them hurt and may even damage our hearing if they are of a sufficiently loud intensity.
To address these sounds, Audition has several real-time restoration effects. For example, the DeHummer effect removes narrow frequency bands — commonly power line hum from lighting and electronics. You can control how broad the band is affected and how quickly it responds by adjusting the Root Frequency and Gain settings.
Loudness is often an important consideration when recording music. However, loudness is a complex topic that can be difficult to understand.
A high maximum threshold setting can reduce clicks and pops in quiet audio, while a low minimum threshold can improve the quality of quiet or muffled vocals. A frequency smoothing (bands) setting can spread the noise reduction into adjacent frequencies to prevent artifacts.
Using a logarithmic scale for amplitude readings more closely mimics how humans perceive sound. A linear frequency response, on the other hand, gives you more control over high frequencies.
LUFS is becoming increasingly important as online streaming platforms adopt loudness normalization techniques, which require all tracks to be recorded at the same level to ensure they appear equally loud. This helps to avoid ‘peaks’ in the track which could cause distortion.