Cumulative Metrics Research Articles

Correlation of airport noise complaint terminology with available noise metrics

In the discussion of airport noise, there is a disconnect between the language used by complainants and the acoustical terminology available to the technical community. It will be shown in what ways the complaint terminology can be described with the available noise metrics and in what ways it cannot. The complaint terminology analyzed comes from the author’s personal (previous) experience as noise control officer at Logan International Airport. Examples of some of these are (aircraft noise is): too loud, too late, too early, unending, continuous, at the wrong time, so loud it sets off car alarms, so loud I cannot hear the TV/telephone/radio, so loud it woke me up, and annoying. Terms which are not related to noise are mentioned, but not correlated. The acoustical terminology comes from the international literature and includes the standard noise metrics as well as some more recently proposed. The airport noise metrics discussed include measures of single events (maximum level, SEL, duration, signal-to-noise) and measures of noise exposure (DNL, CNEL, Leq). It is shown that while cumulative noise metrics are useful for planning and comparison, they correlate with complaint terminology less well than single event measures.

Dynamic Simulation Modeling of an Inspection-Based Software Lifecycle Process

A dynamic simulation model of an inspection-based software lifecycle process has been developed to support quantitative process evaluation. It can be used in project planning and management, and aid in process improvement. The model serves to examine the effects of inspection practices on cost, schedule, and quality throughout the lifecycle. It uses system dynamics to model the interrelated flows of tasks, errors, and personnel throughout different development phases and is calibrated to industrial data. It demonstrates the effects of performing inspections and other managerial policies. The dynamic effects are tracked throughout the time history of a project to show resource usage, task completions and defect trends per phase. Cumulative metrics and development tradeoffs for decision making are also presented. Several types of validation tests are performed against industrial data, existing theory and other prediction models. The results indicate a valid model that can be used for process evaluation and project planning, and serve as a framework for incorporating other dynamic process factors.

Assessment of speech interference from aircraft flyover noise in schools and other communication critical environments

Although most assessments of the effects of community noise impacts on people concentrate on annoyance, it is important in some speech‐critical settings to assess the degree to which noise interferes with communication as well. Speech intelligibility metrics are helpful in such situations, even though they require more detailed information about noise exposure than is captured by cumulative metrics such as the day–night average sound level (DNL). Alternate metrics for assessing speech intelligibility and their uses and limitations will be described. Comparisons will be made between such metrics and those commonly used to assess environmental noise effects on a long‐term average basis.