Concert Halls and Theatres

What do you need to do?

Example: How a conductor can help

The conductor can play a vital part in helping to lower musicians' noise exposure in line with the Noise Regulations. It can be beneficial to understand the common rehearsal and performance practices that can greatly impact on a musician's noise exposure. Some of these control measures could include:

  • Rather than rehearsing the full orchestra, a conductor may choose to undertake sectional rehearsals when they have detailed work with one or more sections of the orchestra.
  • Exploring a greater range of dynamics within the orchestra to create excitement in the variance between a piano and forte marking rather than going for fortissimo could be of benefit.
  • Performing with the orchestra in a number of varying layouts which will give sections occasional respite from traditional 'noisy' areas of the orchestra helps share the load.
  • During rehearsals, once the desired effect has been achieved, allowing the orchestra to play under the marked dynamic.
  • Avoiding unnecessarily rehearsing very loud sections of the score repeatedly.
  • In a full orchestral rehearsal, while making corrections, only working with those particular players or sections who need to be playing at the time and avoid asking other instruments to play.

When programming a concert or a series, a conductor can also be aware that musicians' exposure is measured over a weekly average, so if they were able to programme larger, noisier works balanced out with smaller or quieter pieces, this could reduce noise exposure for their performers. It is also beneficial for an opera and ballet orchestra to rehearse in a space outside the orchestra pit, giving more ambient space to allow sound to escape. Generally the conductor has considerable control over the whole noise output of the orchestra and is able to improve conditions for musicians by being aware of what they are asking of their orchestra.

Case study: Symphony orchestra noise measurement

The orchestra management arranged for a noise assessment of individual members of the orchestra. Measurements were made during rehearsals. The musical repertoire being rehearsed at the time of this noise assessment was:

  • Vaughan Williams: A London Symphony
  • Haydn: Symphony no. 104 in D Major, 'London'
  • Schumann: A Song of Orpheus

80% of the musicians wore individual dosemeters mounted on clothing as close to the ear as practical.

Other measurements were made by sound level meters (SLMs) positioned in strategic locations. These were:

  • just behind and to the left of the conductor;
  • at the centre front of the auditorium (balcony);
  • where the double basses would normally sit (for this rehearsal they were in the centre of the rostra at the rear of the orchestra).

Each SLM was mounted on a tripod, with the microphone positioned at about head height (when seated) and pointing towards the middle of the orchestra.

The key findings were

Dosemeter results
Total number of musicians with valid results 66
No. for whom LEP,d exceeded Upper Exposure
Action Value (85 dB)
26
Highest recorded LEP,d 93 dB
Highest recorded Leq 98 dB
The highest recorded sound levels tended to centre on the brass and woodwind sections, followed by percussion and timpani.
SMLs results over 6h 47m LEP,d dB LAeq dB
Auditorium 76 76
Conductor 79 80
Bass section 80 81

Conclusions

  • A significant proportion (over 30%) of the musicians received a noise exposure in excess of the upper exposure action value of 85 dB during rehearsals of what were considered to be relatively 'quiet' works.
  • Control measures should be implemented and hearing protection worn until the control measures are shown to be effective.

Case study: Musical theatre pit orchestra

The following case study highlights the problems facing musicians when working in the confined space of a theatre orchestra pit.

The musicians performed six evening shows each week with two matinee performances, each lasting about three hours. The assessments were all made under the Noise at Work Regulations 1989.

Initial noise assessment July 2002

Noise measurements taken with four sets of static noise monitoring equipment to establish range of noise levels in the pit.

Measurement position Show LAeq dB Daily noise exposure with one show per day LEP,d dB Weekly average of daily noise exposuresLEP,w dB
Drum booth 92 88 89
Timpani 87 83 85
Conductor 87 83 84
Flautist 92 88 89

Conclusions

  • Replace the previously installed perspex screens with absorbent screens between sections (particularly between brass and woodwind).
  • Place absorbent material on the net at the stage edge to reduce spill from the stage-edge fill speakers into the pit and to make the edge of the pit by the flautist absorbent.
  • Investigate the contribution to the noise exposure of the musicians from the front-of-house stage-edge show sound system.
  • Provide hearing protection.
  • Carry out a further noise assessment to quantify improvement.
  • There would be little benefit in introducing more absorption within the drum booth as this was already 'dead'. The drummer was provided with closed-back headphones with a small mixer and a direct feed from the sound desk which enabled him to control the mix he heard and so reduce the intrusive airborne noise from the drums.
  • Initial assessment should have been carried out on all the musicians to obtain a clearer picture of individual noise exposure. This would have saved costs and time and would have resulted in achieving the reduction in exposure levels sooner.
  • Other recognised noise sources: the sound of a musician's own instrument; the sound of other instruments, especially nearby; the sound of a house sound system, particularly from speakers set into the stage edge over the pit; noise from the auditorium (applause etc).

Second noise assessment August 2002

Noise measurements were taken on the right side of the flautist and the left side of the flautist - to establish any variation from side to side; between the horns and the bass trombone (level with the horn players' left ears); and above the head of the trumpet player.

Measurement position Show LAeq dB Daily noise exposure with one show per day Lep,d dB Weekly average of daily noise exposuresLep,w dB
Flautist right 86 85 86
Flautist left 89 85 86
Horn player/bass trombone 94 90 92
Trumpet 96 92 93

Conclusions

  • Improvements resulting from remedial works in the pit caused a reduction in the LEP,w at the flautist's position of 3 dB. As this position was still above the first action level, hearing protection needed to be made available.
  • After the first assessment it was recommended that the entire perspex screen between the brass and woodwind should have absorbent material fixed to both sides. The first trial would be to have 30 mm dense mineral fibre applied on each side and black wood serge used as a decorative cover stretched over the fibre. The perspex should be left alone for the top section of the screen to allow the brass section to see through it. The mineral fibre should have a minimum density of 60 Kg/m3. If, after these controls have been carried out and reduction is still insufficient, hearing protection should be provided and used.

Third noise assessment September 2002

Noise measurements were taken between violas; between saxophone/clarinet and cello; between French horn and trombone (by horn players' left ears); by trumpeter's left ear; by flautist's left ear.

Measurement position Show LAeq dB Daily noise exposure with one show per day LEP,d dB Weekly average of daily noise exposuresLEP,w dB
Violas 85 81 82
Sax/cello 85 82 83
French horn (left ear) 91 87 88
Trumpet (left ear) 94 89 91
Flute (left ear) 89 85 86

Conclusions

Flautist: further remedial works resulted in a negligible reduction, so hearing protection should be made available.

Brass: the additional absorptive material on the perspex screen in front of the brass position resulted in a significant reduction in exposure levels. Hearing protection should be made available for the French horn but provided to and used by the trumpet.