Date: Sunday, April 10, 2016, 6:00 PM

Place: Boston University, Life Science & Engineering Bldg, 24 Cummington Mall 1st Floor Conference, Room 103, Boston, MA 02215
Guest: David Griesinger

Topic: Equalization of Headphones to Simulate Binaural Listening

I will begin with discussion of the theory behind the procedure, about an hour. Then participants will have a chance to try it on workstations set up around the building You are encourage to bring your own headphones.

The procedure: I have two small computer monitor speakers on two stands, separated by about 25cm.

They each play independent accurately calibrated pink noise. A listener sits in front of the speakers about 20cm away, with the speakers at ear-height. The SPL of the pink noise is about 70dBA

The subject then switches to equal loudness mode, whereby a 500Hz 1/3 octave noise band alternates with a noise band at another 1/3 octave frequency at a one second rate.

The subject adjusts the level of the test band to match the loudness of the 500Hz reference. It is helpful if the room is reasonably quiet – but it does not have to be perfectly quiet, as the bands are at 75dB SPL. We do not test below 200Hz. The subjects personal equal loudness curve is continuously stored as they create it. The subject then puts on the headphones under test, and adjusts for the same loudness as the speaker. Once again they perform the equal loudness tests as the values they find are stored in another memory bank. In this case all bands are tested, including LF. Once the subject is satisfied they can test another pair of headphones, up to five.

With the data collection finished, they can switch on music of their choice – if they brought a smartphone or the like. My computer will have binaural recordings from famous halls, which are absolutely stunning, and very hard to turn off. They can switch the eq on and off, or play with it a bit if they want.

There will be refreshments at 5:30

— Webmaster's note: Those of you interested in this test and its procedures might enjoy both my white paper here: www.soundoctor.com/testcd/whitenoise.htm and also a rather fascinating discussion / demo of this pink noise phenomena by Dave Rat, on youtube, here: https://youtu.be/VHjdh-Vka-g