A SOUND EAR II - Association of British Orchestras

A SOUND EAR II
Equipment
Measurement equipment shall meet the following specification:
• Individual noise monitoring devices shall be designed to securely fix to the clothing of the musician without risk
of damage to delicate clothing. Tripods shall not be used for mounting measurement equipment to measure noise
exposure of musicians.
• When attached, the device shall not cause any restriction to movement for the musician wearing it.
• Devices shall be compliant with BS EN 61252:1997 Electroacoustics. Specifications for Personal Sound Exposure Meters.
• Devices shall measure and record L Aeq
up to at least 130dBL Aeq
.
• Devices shall measure and record peak levels up to at least 140dB(C).
• Devices shall measure time histories of the above parameters averaged across 1 minute time intervals.
• Devices shall not emit any noise during operation or standby.
• Devices should not emit any light during operation. If light is emitted, the light source shall be covered with a nontranslucent
tape during measurements.
• All devices must be calibrated bi-annually using equipment referenced to the British Calibration Service, and the
National Physical Laboratory.
Examples of equipment which meets the requirements are:
• Cirrus Research CR:110A doseBadge Person Noise Meter with RC:110A Reader Unit
• Casella CEL-350 dBadge Noise Dosimeter
In addition to the personal noise monitoring devices, a single sound level meter shall be mounted on a tripod next to
the conductor’s desk, ensuring that the tripod does not restrict access to any of the performer positions. The sound
level meter shall have all of the functionality described for the personal noise devices and shall comply with BS EN
61672-1:2003 Electroacoustics. Sound level meters. Specifications.
37
Measurement Method
All musicians shall be made aware of the dates of monitoring at least a week in advance. The specific musicians to be
monitored shall arrive in good time before the start of the rehearsal or performance (ideally 15-20 minutes) to have
their personal devices fitted.
All clocks on the measurement devices shall be synchronised before fitting to musicians.
To obtain a reasonable record of the sound level distribution in the pit, a minimum of seven personal devices shall
be used, in addition to the sound level meter at the conductor’s position. For large orchestras, more devices are
recommended.
Personal devices shall be fitted to either shoulder of the musician as close to the ear as possible without restricting
movement.
Personal devices must remain running during intervals/breaks. They would preferably remain fixed to the musician
during this time. Musicians should be aware that they do not record conversations, just statistical data. If devices are
removed during such breaks, they must be refitted in the same location before playing recommences.
If different works are performed during a single performance, the software provided with the equipment shall be
capable of isolating the different time histories for the different pieces.
At the end of the session, devices must be left on music stands for collection by the noise monitoring coordinator.
The calibration of all measurement equipment must be verified before and after use (using an internal acoustic
calibrator to IEC 60942:2001 Class 2) and any observable drift noted.