Re: sound events database

Hi Ernesto,

Over many years we have built up a library of recordings made in and around aircraft that provide the guidance levels we need for these more generic traffic sounds. These are calibrated using cal tones on each recording.

Even having this information does not stop pilots from making subjective requests to make certain sound cues louder or softer based on their perception - this is often due to personal experience with a particular situation by that specific pilot. For example KLM at Schipol (Amsterdam) airport may use a particular type of pushback truck, one that is different from our standard sound reference, and hence, despite the fact I have aircraft recordings with calibration tones, etc, of a similar pushback vehicle, I will be requested to retune the sound either louder or quieter as requested.

Unfortunately I'm not personally aware of a single consolidated database that will provide a wide-range of sound events and corresponding SPL/distance figures, but there may be others on the list that have suggestions.

Regards, Neil

On Apr 22, 2010, at 10:33 AM, Ernesto Accolti wrote:

Dear Neil.

You are right. Both, the sound events database and an SPL at known
distances database can be sufficient. However I'm not sure if it is
easy to access to this two databases and adapt each data or making
myself the (calibrated) recordings.
I think that I will need more than 100 sound events.

How did you solved the problem of the ground traffic? Did you had to
measure yourself the typical SPL at known distances?

Thanks!

Ernesto.

2010/4/22 Neil Waterman <neil.waterman@xxxxxxxxxxxx>:

Surely what you really need is a database of typical SPL levels for certain
sound sources at known distances?
I work for a company producing Level D certifiable sound systems for use in
the highest fidelity sound systems, and reproduction must EXACTLY match the
source aircraft, but once you accept general sounds (as opposed to SPECIFIC
ones) there is no reference SPL only representative levels - I face this
problem when representing the ground traffic around the aircraft while on
the ground (push-back trucks, luggage carts, etc)
- Neil