Investigation of Tonal Noise

Press Release

NÆRUM, DENMARK, DECEMBER, 2007

Investigation of Tonal Noise

With an award-winning design and based on extensive research amongst sound and vibration technicians, engineers and consultants, Type 2270 and 2250 Hand-held Analyzers are both innovative, 4th generation analyzers from Brüel & Kjær.

Type 2270, with its dual-channel measurement capability, and the single-channel Type 2250, host many of the same measurement application modules. One of these is the Tone Assessment Option BZ-7231.

Noise can be described as tonal if it contains a noticeable or discrete, continuous note. This includes noises such as hums, hisses, screeches, drones, etc. and any such subjective description is open to discussion and contradiction when reported.

As the objective measurement result can be comprehensive in its detail, it can also be helpful to have a sound recording of the noise for a non-technical audience to listen to subjectively. To hunt for a tone, Type 2270/2250 can be used in a manner similar to a hand-held amplifier with headphones connected to the headphone output, and the microphone signal played through the headphones. You can then amplify the signal in real-time in 1 dB steps. This enhances the operators hearing to be able to hear low level tones which the complainant may be more tuned to, or in some cases, to deduce a tonal element as being a hearing damage issue, for example tinnitus, rather than anything physically present in the acoustic environment.

With the FFT-based Tone Assessment Software the easy, safe and clever approach of Type 2270/2250 is embodied in the easily visible colour display, the very high frequency resolution offered by up to 6400 lines of analysis, the wide dynamic range and the clever tap-and-drag operation of key display and measuring features.

Type 2270 and 2250 Hand-held Analyzers meet head on the demands of todays wide-ranging sound and vibration measurement tasks with the accuracy and reliability associated with Brüel & Kjær instrumentation.

Can such a compact yet powerful instrument also be intuitive and easy to use? To experience the ease-of-use of Type 2270, please view the on-line video demonstrations, or enjoy Type 2250s Interactive Tour.

For More Information
Contact Brüel & Kjær, Tel: +45 45 800 500, e-mail: info@bksv.com