Unlocking the secrets of NEC's "EuphoMagic" acoustic signal processing technologies, which make conversation easy and dramatically improve voice recognition rates even in noisy environments
When talking on a mobile phone or smartphone, have you ever found it difficult to hear the other person's voice because of the noise around them? Voice recognition also tends to fail most of the time in places with background noise, even when speaking directly into the microphone. This always causes me a lot of frustration.
Just as I was wondering if anything could be done, I was surprised to learn that NEC has developed a set of cutting-edge acoustic technologies for removing this kind of noise. This is "EuphoMagic," which we'll be looking at today. Apparently it significantly reduces noise during phone calls, and makes voice recognition easier, while also incorporating new proprietary technologies! I wasted no time going for a face-to-face interview with the EuphoMagic research and development team to hear more!
Mr. Miyahara specializes in audio signal processing. He is currently assigned to the EuphoMagic research and development team, where he is involved in the research and development of technologies related to noise cancellation and noise suppression for phone calls in particular, which are used in noise cancellers and noise suppressors.
Mr. Tsujikawa is a member of the EuphoMagic research and development team. Since joining NEC, he has dedicated his work to the research and development of technologies related to voice recognition in noisy environments.
- MitaIt's a pleasure meeting you, Mr. Miyahara and Mr. Tsujikawa. Getting straight to the point, what exactly is EuphoMagic?
- MiyaharaPut simply, EuphoMagic is a suite incorporating a variety of acoustic signal processing technologies. That may sound a little cryptic, so let me explain in a bit more detail. First, I have a question for you. Broadly speaking, there are two things that can recognize voices. What do you think they are?
- MitaWell, people...and what else, I wonder?
- MiyaharaThe other one is machines. This includes devices like smartphones and car navigation systems. For both human and machine voice recognition, our goal is to deliver only the requisite audio to the other party, making it easier to convey information.
- MitaI see.
- MiyaharaHowever, in spacious areas a variety of other sounds are often present along with the audio you want to convey. As you can imagine, this results in the microphone picking up a range of sounds as noise. When this unwanted noise is picked up, it makes it harder for the other party to hear what you are saying. For this reason, it is necessary to process the acoustic signal using a variety of technologies, such as noise reduction, to convey only the required audio.
- MitaSo you're saying that EuphoMagic is a collection of these acoustic signal processing technologies?
- MiyaharaThat's right. There are two main approaches to this system: one for communicating information to humans, and the other for communicating it to machines. Each involves different processing methods, so I'll start by covering cases in which audio is conveyed to a person.
Communicating audio to humans
- MiyaharaWhen conveying audio information to people, we combine technologies such as a noise canceller or noise suppressor for eliminating or reducing surrounding noise, and an echo canceller for removing echoes and howling. You have a smartphone with you today, right? Can you check whether it has two microphones?
- MitaTwo microphones? (She takes her smartphone out of her pocket and checks...) It does! There's a microphone where the mouthpiece is, and another at the top.
- MiyaharaThese days a lot of smartphones and mobile phones actually have microphones at both the mouthpiece and top area.
- MitaWhy do they have two microphones?
- MiyaharaWhen talking hands-free on a smartphone, a sharp howling sound is produced if the microphone and speaker are too close. Switching to the secondary microphone at the top resolves this issue.
- MitaI see.
- MiyaharaIt also makes efficient noise reduction possible. These two microphones are used in technology known as "noise cancellation" that drastically reduces noise. This is a crucial technology, so allow me to explain further.
- MitaHow is the noise eliminated?