Noise Suppression Options for Field Recording
Noise suppression and reduction software are effective tools for reducing unwanted background sound when recording in difficult, noisy acoustic environments. Although there are many options for noise reduction via a computer, there have been few portable options for running real-time noise suppression live in the field. CEDAR’s stand-alone noise suppression units have been popular choices for sound professionals who needed portable real-time noise suppression on-location. Now, for the first time in production sound history, adaptive, real-time noise suppression is available directly in a mixer-recorder with Sound Devices NoiseAssist and CEDAR sdnx. No additional hardware is required.
Because noise suppression algorithms change the audio signal, it is always best practice to record “raw” tracks without noise suppression. Noise suppression may be applied to buses or additional copies of isolated record tracks, or during post-production. However, in applications such as live broadcast and streaming, fast turnaround productions where there is no time for post, communications feeds, and daily tracks, the benefit of real-time noise suppression is significant.
Let’s discuss options for real-time noise suppression and their operating platforms.
1. Use NoiseAssist/CEDAR sdnx in a Sound Devices mixer-recorder
Sound professionals with Sound Devices mixer-recorders can use the optional NoiseAssist plugin to apply real time noise suppression to ISO channels or the left or right bus. The plugin allows for up to eight instances of NoiseAssist (8-Series), or one instance (MixPre II Series).
CEDAR sdnx brings CEDAR Audio Ltd.’s highly-regarded noise suppression technology to 8-Series mixer-recorders. Choose between 2, 4, and 8 instances that can be applied to any channel or bus!
| Product | Host Platform | Latency | Notes |
| NoiseAssist | 8-Series/MixPre II Series | 1 ms | Integrated in the mixer when installed |
| CEDAR sdnx | 8-Series | 13 samples | Integrated in the mixer when installed |
2. Use a CEDAR DNS-2
This CEDAR hardware connects to a field mixer-recorder to offer two-channels of noise suppression. Though less portable and more expensive than the built-in NoiseAssist plugin, this CEDAR model yields excellent results and is popular in the industry. There are also larger CEDAR units that offer additional channels of noise suppression.
| Product | Host Platform | Latency | Notes |
| Cedar DNS-2 | Cedar DNS-2 | <1 ms | Stand-alone unit w analog and digital I/O, requires 12 VDC powering |
3. Bring a computer to location
When gigs require portability, including a computer in your kit may not be the most practical. However for larger, more permanent setups, running DAW software with plugins may be an option. Adding a computer can increase the complexity of a kit versus hardware systems like NoiseAssist or CEDAR. Additionally, while a plugin may not introduce latency on its own, the computer and audio interface may introduce significant latency. Because of this, computer-based setups may not be the best option for live, real-time noise suppression.
There are many noise reduction softwares available. The following is not a comprehensive list.
| Product | Host Platform | Real-time | Latency | Notes |
| Cedar Studio | MacOS/Windows | unknown | unspecified | Software and plugin version of the hardware-based DNS |
| iZotope RX | MacOS/Windows PC stand-alone or plugin | Yes, plus post-record | unspecified | Very powerful tool for post-production noise reduction |
| Waves WNS, Waves W43,Waves Z-Noise | MacOS/Windows PC, common plugin architecture | Yes, plus post-record | 0 (plugin only) | |
| NVIDIA RTX Voice | Windows PC + NVIDIA RTX GPU card | yes | >50 ms | GPU consumes >30 watts when active |
| Avid DINR | MacOS/Windows PC ProTools plugin | no | – | |
| Antares Sound Soap | MacOS/Windows PC standalone or plugin | no | – | |
| Adobe Audition included plugin | MacOS/Windows PC running Audition | no | – |
4. Fix it in Post
If a post-production team and time are available, it can be best to leave noise suppression to them and focus on getting the appropriate signal-to-noise ratio on location.
There are many viable options for noise suppression or reduction. Computer-based software solutions can be ideal for post-production, non-real-time noise reduction, or fixed setups. CEDAR noise suppression units are popular in the industry for portable, real-time noise suppression. NoiseAssist and CEDAR sdnx are ideal for sound professionals requiring a lightweight kit with maximum portability, minimum latency, and affordable real-time noise suppression.
More reading: 6 Ways to Reduce Noise While Recording Dialog