Modelling the effects of spectators on speech intelligibility in a typical soccer stadium

Abstract

Public address system performance is frequently simulated using acoustic computer models to assess coverage and predict potential intelligibility. Simulations are most-often completed in unoccupied spaces as this provides worst-case scenario intelligibility due to the reduced absorption. When the typical 0.5 speech transmission index (STI) criterion cannot be achieved in voice alarm systems, due to design difficulties, justification must be made to allow contractual obligations to be met. An expected increase in STI with occupancy can be used as an explanation, though the associated increase in noise levels must also be considered. However, numerous approaches exist when modelling the people which can produce significant discrepancies. This work demonstrates typical changes in STI for different spectator conditions in a calibrated stadium computer model. This includes different audience modelling approaches, distribution, capacity, posture (standing/seated), and atmospheric conditions. The effects of ambient noise are also considered. The results can be used to approximate expected changes in STI caused by different spectator conditions.Public address system performance is frequently simulated using acoustic computer models to assess coverage and predict potential intelligibility. Simulations are most-often completed in unoccupied spaces as this provides worst-case scenario intelligibility due to the reduced absorption. When the typical 0.5 speech transmission index (STI) criterion cannot be achieved in voice alarm systems, due to design difficulties, justification must be made to allow contractual obligations to be met. An expected increase in STI with occupancy can be used as an explanation, though the associated increase in noise levels must also be considered. However, numerous approaches exist when modelling the people which can produce significant discrepancies. This work demonstrates typical changes in STI for different spectator conditions in a calibrated stadium computer model. This includes different audience modelling approaches, distribution, capacity, posture (standing/seated), and atmospheric conditions. The effects of ambi...