PTB supports development of effective sound insulation for orchestra musicians

EU Directive 2003/10/EC defines increased requirements for the protection of employees against noise hazards. The practical realization, which has Europe-wide been demanded until February 15, 2008, represents a serious problem, especially for the musicians of a symphony orchestra,

as it has so far been possible to comply with the required sound level values during the working hours only by a personal sound insulation, i.e. blockage of the auditory cannel with suitable earplugs. To perform highly demanding music, this is, of course, hardly acceptable as especially the orchestra musician controls his own music and the interplay with his fellow musicians via the ear. As an alternative, possibilities should be sought for as to how the sound can be reduced by suitable measures at places in the orchestra where hearing is particularly at risk. For this purpose, it was investigated within the scope of a joint project of PTB, the Municipal Theatres Münster, and the Gemeindeunfallversicherungsverband Westfalen-Lippe whether it is possible to prevent by special sound insulation walls the level of brass instruments (especially trumpets and trombones) - which in fortissimo can increase up to 120 dB(A) - from acting directly on the ear of musicians sitting directly in front of these instruments.
As a result of these investigations, a sound insulation screen has been developed by the two project partners within the scope of the third-party-funded project whose efficiency could be evidenced in the critical frequency range above 250 Hz. With the aid of this screen, the sound levels above 4 kHz could be reduced by more than 20 dB, whereby the achieved value strongly depends on how far the musician to be protected is away from the sound insulation screen. Practical investigations have shown that at a distance of 50 cm, one's own play is hardly impaired by the screen, but that the sound intensity coming from the brasses is considerably reduced.

Figure 1: Sound insulation screen for the protection of musicians against high sound levels

Contact person:

Ingolf Bork, Department 1.7, WG 1.72, E-mail: Ingolf.Bork@ptb.de