Featured Research

from universities, journals, and other organizations

Measurement scientists set a new standard in 3-D ears

Date:
October 17, 2010
Source:
National Physical Laboratory
Summary:
Scientists have developed a means of representing a 3-D model ear, to help redefine the standard for a pinna simulator (the pinna is the outer part of the ear) -- used to measure sound in the way we perceive it.

This is an image of the NPL artificial ear.
Credit: NPL

Scientists at the UK's National Physical Laboratory (NPL) have developed a means of representing a 3D model ear, to help redefine the standard for a pinna simulator (the pinna is the outer part of the ear) -- used to measure sound in the way we perceive it.

The nature of human hearing is heavily dependent on the shape of the head and torso, and their interaction with sound reaching the ears allows for the perception of location within a 3D sound field.

Head and Torso Simulators (HATS) are designed to model this behaviour, enabling measurements and recordings to be made taking account of the Head Related Transfer Function (HRTF) -- the difference between a sound in free air and the sound as it arrives at the eardrum.

HATS are mannequins with built-in calibrated ear simulators (and sometimes mouth simulators), that provide realistic reproduction of the acoustic properties of an average adult human head and torso. They are ideal for performing in-situ electro-acoustic tests on, telephone handsets (including mobile and cordless), headsets, audio conference devices, microphones, headphones, hearing aids and hearing protectors.

Critically the shape of the pinna has a large effect on the behaviour, and as a result it is defined for HATS by its own standard (IEC TR 60959:1990) to provide consistency across measurements. However, this standard defines the shape of the pinna through a series of 2D cross-sectional profiles. This form of specification and definition has on occasion proven to be an inadequate guide for manufacturing processes.

As part of a revision of this standard, the Acoustics Team at NPL teamed up with the National Freeform Centre in a novel move to redefine the standard through an on-line 3D CAD specification. A model ear was measured using a coordinate-measuring machine with laser scanner to produce a 3D scan of the ear, which can then be used to provide manufacturers with a more practical specification for reproduction and a standard that is easily comparable with similar non-contact freeform measurement techniques.

Ian Butterworth from NPL, said: "Having a 2D pinna in an artificial ear has some inherent frequency limitations. For example, when sound spreads through structures like narrow tubes, annular slits or over sharp corners, noticeable thermal and viscous effects take place causing further departure from the lumped parameter model. The new standard for the 3D model has been developed to give proper consideration to these effects. We worked with the National Freeform Centre, experts in measuring items that are unconventional in shape or design, to develop the new standard -- which will now help manufacturers develop better products."


Story Source:

The above story is based on materials provided by National Physical Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

National Physical Laboratory. "Measurement scientists set a new standard in 3-D ears." ScienceDaily. ScienceDaily, 17 October 2010. <www.sciencedaily.com/releases/2010/10/101012101251.htm>.
National Physical Laboratory. (2010, October 17). Measurement scientists set a new standard in 3-D ears. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2010/10/101012101251.htm
National Physical Laboratory. "Measurement scientists set a new standard in 3-D ears." ScienceDaily. www.sciencedaily.com/releases/2010/10/101012101251.htm (accessed July 25, 2014).

Share This




More Health & Medicine News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Newsy (July 24, 2014) Sheik Umar Khan has treated many of the people infected in the Ebola outbreak, and now he's become one of them. Video provided by Newsy
Powered by NewsLook.com
Condemned Man's US Execution Takes Nearly Two Hours

Condemned Man's US Execution Takes Nearly Two Hours

AFP (July 24, 2014) America's death penalty debate raged Thursday after it took nearly two hours for Arizona to execute a prisoner who lost a Supreme Court battle challenging the experimental lethal drug cocktail. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
Can Watching TV Make You Feel Like A Failure?

Can Watching TV Make You Feel Like A Failure?

Newsy (July 24, 2014) A study by German researchers claims watching TV while you're stressed out can make you feel guilty and like a failure. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins