I am the developer of the tbone Aviation Headset and somebody turned my attention to this forum and this specific thread.
I will be happy to answer any questions users of this forum may have, but I will also try not to mis-use this thread for marketing purposes.
The story behind the headset is briefly this:
In 1999 I worked at a Danish company who held the patent of the special in-ear-bone conducting microphone that was developed to be used with hand held VHF radios.
In an attempt to widen the product range I contacted some pilots in CPH, and from their input I designed the tbone Aviation Headset (originally developed under the name Invisio Aviation Headset).
The product was thoroughly tested in SAS (15 pilots) and Delta Airlines (22 pilots) - all on the B737.
The tests were positive and 'Prove of Concept'.
As the next step was TSO qualification, the project was turned over to Terma (www.terma.com (http://www.terma.com/)) who now hold all rights to the tbone Aviation Headset.
The headset acquired the ETSO 57a & 58a in October 2005 and we expect the FAA LODA (Letter of Design Approval) very shortly (before end of April 06).
The main concerns pilots have before purchasing the headset are:
- The price ($995)
- The microphone
- The comfort
The price of $995 is mainly due to the fact, that this is a customized and hand made product.
The manufacturing process is very similar to that of hearing aids with two major differences:
1) The special bone pick up system is expensive and requires highly skilled labor to install.
2) The durability is much higher than that of a hearing aid as the headset must meet the tough DO-160 environmental criteria to qualify for the ETSO. This involves a very demanding drop test where the headset is dropped from 1 meter to concrete floor 12 times in first normal indoor temperature, then heated to 65 degree Celsius and dropped again 12 times and finally frozen to minus 55 degree Celsius and dropped 12 times.
The headset must be un-effected by this - try this with a hearing aid!
Also please compare the tbone headset price to the price of two custom molded hearing aids, and in this comparishment the tbone is actually very cheap!
The other concern is the microphone. Does it sound different? How about the readability?
As part of the ETSO certification we were required to have a certified testing company perform an intelligibility test.
This was done using 10 pilots equipped with a tbone headset.
The setup was a virtual cockpit with a calibrated sound environment of a B737-700. The sound was measured and recorded on a flight from CPH to STR. The 1 minute with the highest density of noise was then played back continuously in the virtual cockpit at calibrated level.
At the listening point a virtual tower was build in the same way using sounds from CPH tower.
The pilots then read a list of 50 different words that the listener had to recognize and write down. Each pilot read from his own list and no list contained the same words.
In the test the tbone was compared with a high quality headset.
The tbone would qualify if more than 80% of the words were perceived correct. The 80% would ensure 99% context perception.
The reference headset scored 95% and the tbone headset scored 93%.
It was also established (although not a part of the official test and therefore not reported) that if the traditional headsets boom mike was not 100% correctly placed the intelligibility were poorer than the tbone due to lower signal to noise ratio or distortion.
Having said that, it is true that the sound of the voice is different. Many report the sound as 'speaking in a bucket'. It is a hollow sound.
But readable!
During my many hours on jump seat I have heard many transmissions where the voice sounded 'natural' but was almost complete unreadable if the mike was not positioned correctly (angle and distance from mouth).
On the comfort issue - I know there are some people who cannot have anything inserted in their ear. These people tend to get rash or irritations very easily - maybe because they remove the natural protection - the ear wax - with a cotton pin each morning.
We have not yet seen any reports from users with this problem.
Another comfort issue with ear pieces is the fact that the user hears his 'inner' voice much louder. Try putting a finger in each ear and then speak - then you will know the sensation.
But this is something the users get used to very quickly - especially in a noisy environment, and especially pilots who are used to the 'side-tone' in their headset.
In Terma we believe this headset has a few advantages compared with a traditional boom headset but as I started this post by renouncing all marketing efforts you must turn to the products website to read about that.
One factor that many pilots (but not all!) report is that they like the headset not having Active Noise Reduction, but solely rely on passive reduction.
They report that they appreciate the fact that they can actually hear all sounds - only at a reduced level. They report that using their hearing sense is vital to their control of the flight.
Others - those who loves ANR headsets - does not appreciate the level of noise reduction in the tbone. As they can actaully hear everything that goes on around them they seem to think that the noise reduction is too little.
One last issue - we cannot make this headset to everybody! Some people have very narrow ear canals that will not support the space needed for the microphone. We estimate 5% of the population will not be able to use this headset.
If you have questions please post them here in this thread as I am sure other interested pilots may want to know the answers.
We have a few airlines testing the headset around the world (mainly in US, Europe and South East Asia).
These evaluations are conducted by pilots selected by the airline.
The evaluations are free of cost (paid by Terma), contains no buy-obligations and they usually runs for 3-4 month.
If you are a CP or a TP you may contact me on
[email protected] if you want to know more about these evaluations.
Sincerely
Jan Thostrup
Sales Manager, Audio Systems
www.tboneaviation.com (http://www.tboneaviation.com)