Binaural Audio – The Technology

To create binaural audio, our normal hearing has to be replicated. To do this, a few different forms of equipment can be used, these are demonstrated in the figures below.

766_1400
Figure 1 is of a Dummy head that has the microphones build into the ears. They are very costly at around £4,500 from Neumann, however they do replicate the human head and the intricacies of the ears, therefore creating a more realistic binaural audio.
Figure 2 is of in-ear microphones, these are less expensive at around £70 – £100. They are placed into your own ears and record what you would hear in the environment surround you.
Figure 3 is the 3Dio microphone, starting at around $499. Similar to the Neumann dummy, they replicate the human ears and record the audio from the microphones inside the ears.

screen-shot-2016-11-24-at-10-01-52

Although those are the different ways to record live/real-time binaural audio, the effect of binaural audio can also be replicated in post-production editing suites, by changing the volume and position of the Left and Right channels. This can easily be done in editing softwares such as Adobe Audition, which is what I will choose to test on as it is easily accessible to me, and I have prior knowledge of the software so I should be able to make something simple fairly easily.

Another way of simulating the binaural audio in an editing suite, is by mixing with Dolby Digital 5.1 surround sound. This can be done in Adobe Audition as they have an extensive section for mixing in 5.1. Dolby 5.1 is meant to be used with 5.1 speakers, giving surround sound when watching films, using 2 speakers behind the user (left shoulder, right shoulder) and two speakers in front of the user to the left and right. However the effect 5.1 created is very similar to the effect I am wanting to re-create for binaural audio, therefore I will be testing this method to see how it sounds.

Advertisements

Initial Ideas

29Here is a list of my initial ideas of what I could create using binaural audio:

  • 360º video recording of live event
  • Create a VR scene
  • Light show with 360º sound effects (in connection with my dissertation)
  • Motivational in ear speaking while doing exercise
  • Audio for a theatre performance/film screening

In my spare time I enjoy going to music concerts, therefore one of my initial ideas for this project was to make an immersive virtual experience of a music concert. This would include filming the concert on a 360º camera, as well as recording the audio binaurally. The video would then be put inside a VR headset and the audio would be listened to through headphones. The idea would be to give the illusion that the user is at the concert, rather than in their existing environment.

screen-shot-2016-11-23-at-23-44-28

A second idea I had was to create my own VR scene, for the Oculus Rift. The VR scene could be anything from a beach scene to a woodland scene as long as it can include various sound effects that would surround the user. These could include birds or aeroplanes flying overhead, waves crashing, leaves rustling and people talking, giving the effect that the user is in the environment. The audio for this would be created using various sound effects, then using an audio-editing software such as Adobe Audition, I would change the volume levels of each clip for the two different channels to give the illusion of the sound effects surrounding the user in 360º.

Another thing I like to do in my spare time is going to the gym, which was an influence of another idea. Though using binaural audio, I thought I could simulate the personal trainer/instructor experience. Some people may find it daunting/intimidating and even expensive to book a personal trainer, so my idea would be to have the sound of someone telling you what to do. This would play alongside motivational music and would be tailored to which sport you were participating in. The sound of the trainer would only be from the rear 180º as it would not feel realistic if the sound was being heard from in front of the user but there was no one there. The idea of this is to motivate the user either at home or in the gym, without the pressure and expense of getting a personal trainer/instructor or booking into a group class which may intimidate some people.

A final idea is to put the technology of binaural audio to use within a theatre or cinema environment. In my opinion, the overall experience of the theatre or cinema could be greatly heightened if the audience could listen binaurally, especially in the use of 3D cinema where part of the immersive experience is there with the glasses.

Binaural Audio – how it works

Binaural audio works on the premise of capturing the audio from the 360º space surrounding the microphones, making the playback very similar to our normal hearing. As sound reaches the listener, depending on the origin of the sound, it reaches each ear at different times and at different volumes – binaural audio recordings catch the very smallest detail of the surrounding sounds to create an immersive audio experience for the user.

Stereo recording does not account for the physical intricacies of our hearing – binaural audio also takes into account the shape of our ears, and how the sound moves around the outer ear, before reaching the inner ear canals. Binaural recording tricks your brain into thinking that what you are listening to is actually occurring in the space around you.

binaural_audio_1-01

Introduction to my ideas

From the get-go, I have known that I wanted to create a completely immersive experience for a user/audience. I have always been interested in the concept of escapism, and allowing a user to situate themselves in a different environment to where they currently are.

I remembered from years ago an audio piece I listened to called the virtual barber shop. The piece instructed me to put on headphones and shut my eyes. From the audio that was playing, it felt as though I was in a barber shop having a real haircut.

I was really fascinated by this and how audio could trick the brain into feeling like it is somewhere else, and I knew I wanted to explore this idea along with the use of a visual aid. After researching, I found that this technology is called Binaural Audio and that it has been used for many years, but not used widely.

I have chosen the technology of binaural audio to work with because I feel it is very under-used for the effect it has on the user. When used in combination with a virtual visual environment, it creates a completely immersive experience, where the user feels like they have been transported into a different environment to where they currently are. Virtual reality is about a change of multiple senses to ensure the user feels like they are in an alternate environment and eventually I imagine some VR installations to include a change of smell, taste and touch, as well as sight and sound.

About the Developing Media Design Concepts unit

The Developing Media Design Concepts unit is about the plan and preparation for our Graduate Project. Within this unit I will be exploring various different routes and ideas, before coming to a final and rounded conclusion of what I shall be creating for my final graduate project. I will frame my idea around various social and contextual ideologies, as well as planning and preparing all that I can to ensure my final project goes as smoothly and successfully as possible.

Part of the unit is to create a dossier of our work as we travel through the creative process, and I have decided to present my dossier in the form of this blog. I have chosen this medium because it gives me more flexibility on the types of input and output I can display, such as video and audio clips. Anything within the DMDC category or tagged with DMDC will be part of the dossier.