Turn an Ear to Hear
How hearing-impaired listeners can exploit head orientation to enhance their speech intelligibility in noisy social settings.
Turn an Ear to Hear is a research project that discovered that listeners in a noisy situation benefit from facing slightly away from the person they are listening to, turning one ear towards the speech.
Natural and easy
The method only requires a slight turn of the head to be effective meaning it is possible to use in every day situations without a lot of effort. It was also found to be especially beneficial for cochlear implant users who typically struggle in noisy social settings such as restaurants.
Compatible with lip-reading
Our data showed that the benefit of lip-reading was unaffected by a modest, 30-degree head orientation. The benefits of lip-reading and turning an ear towards a talker can therefore be combined.
The research showed a 4-decibel improvement to intelligibility of speech in noise experienced by normal-hearing listeners and cochlear implant users in our laboratory. A 4-decibel improvement can be the difference between understanding nothing and perfect understanding. The speech was in front of the listener and interfering noise behind.
How data were collected
Study participants attended to target speech from a loudspeaker in front of them with noise coming from a loudspeaker placed behind them. Speech intelligibility was measured with and without accompanying video, so the benefit of lip-reading could be calculated. Listeners either faced the speech or (still watching the video) oriented their head 30 degrees to one side.
Works in real-life environments
Turning an ear to hear worked very well in a sound-treated lab, but would it work in real life? Our data showed that it does.
How the data were collected
To simulate a realistic restaurant listening situation, acoustic measurements were taken in Mezza Luna, a real restaurant in Cardiff, and used to create a virtual acoustic simulation. In the simulation normal hearing listeners were tested at each table with three different head orientations: facing the target talker, with a 30-degree head turn to the left, or with a 30-degree head turn to the right.
These measurements were then used to make very realistic headphone simulations of the restaurant with nine customers at other tables talking at once (five female and four male). In some conditions, the other customers were replaced with noises (like radio static).
Listening through the headphones, it sounds exactly as though one is in the restaurant, sitting at one of six chosen tables, with occasional test sentences coming from a male voice across the table.
The two experiments allow for conclusions to be made about the causal effect of head turning on the understanding of speech in both a laboratory and a real-world setting.
Funded by UK charity Action on Hearing Loss (RNID).