One of our sales reps tells a story about visiting a television station in Chicago. When he walked into the studio, he saw banks of telephone couplers, all plugged in to POTS (Plain Old Telephone Service) lines. These were being used for IFB – teams in the field would call in using their cellphones, they’d connect and be able to listen to program or mix-minus audio from the studio.

Comrex EarShot IFB

But as we all know, POTS lines are becoming more and more expensive. And if you need to pay for 10, 20, 30 lines or more – it’s not a cheap undertaking. Many customers have told us that they wished they had a VoIP auto-coupler, that could connect to their new VoIP infrastructure for intercom.


An Overview of VoIP Technology, How It Works, and How To Use It

We built EarShot IFB to bring the power of VoIP to IFB technology. EarShot IFB is a hardware-based system that delivers live audio feeds to callers.

EarShot IFB is designed to provide telephone-based live studio program and IFB audio to field-based remote broadcasts, like TV ENG reports. Up to 30 callers can dial in and listen to the audio feeds, making it possible to replace multiple POTS-based couplers with one simple box.

Up to 30 POTS Lines

With SIP protocol, EarShot IFB interfaces with Voice-over-IP (VoIP) telephone circuits. Because of this, it’s possible to replace up to 30 POTS lines with EarShot IFB.

And you don’t have to skimp on audio quality either – EarShot IFB can interface to most normal calls using standard telephony audio encoding (G.711).

EarShot IFB can also deliver audio to “pure” end-to-end VoIP callers with higher fidelity, using encoders like G.722 and Opus.

Multiple Callers

EarShot IFB can handle 30 telephone-based calls, or 10 wideband calls. Alternately, you could have a combination of each!

(One wideband call is equal in bandwidth to 3 POTS calls. So you could have EarShot handling 2 wideband calls and 24 POTS calls or whatever combination works for you.)

VoIP phone lines can be delivered from cloud-based VoIP providers, VoIP-based PBXs (in many cases), and via hardware gateways devices that bridge legacy phone circuits (e.g. T1/E1, POTS) to VoIP.

You can also call into EarShot IFB with FieldTap, our new smartphone application for better quality drop-ins.

(For math and planning purposes, FieldTap calls are wideband calls!)

Audio Feeds

EarShot IFB has four audio inputs (or feeds). Two of the feeds can be alternately configured as IFB inputs. Up to 30 callers can dial in and listen to audio from standard telephones. Callers can switch between the feeds using DTMF (Touch Tone) selection.

Selectable Feeds

EarShot IFB features selectable feeds. Users can configure some feeds with full program audio, and implement mix-minus on other feeds to prevent echo and other audio flaws. This versatility makes it simple to tailor EarShot IFB to your needs.

EarShot IFB fills a real need in live television production for flexible, IP-based IFB. Whether you’re covering live sports, tracking news from the field, or are producing some other live program, EarShot IFB is a versatile IP solution (that can also save you some cash).

Learn more about EarShot IFB!

Have questions? Contact us!

Want to demo gear? Request a loaner.

Interested in purchasing? Reach out to an authorized audio dealer or video dealer.

*Note: Demos available for US residents ONLY.