scope:

The purpose of this guide is to define procedures that will permit the comparison of the acoustical performance of various types of household or similar sound radio receivers, in a controlled environment and with an established procedure, to give results that are as reproducible as possible. The listening tests are carried out by comparison against a reference receiver. However, this does not exclude that certain qualities and impairments may be characterized by absolute judgements. The reference receiver must be selected with great care in all cases because the comparative judgements made are dependent on this reference. A description of the reference receiver must also be given with the results. A subjective evaluation, based on this guide, consists of the average judgement of several persons on a given subject. The individual opinions are divided into ranges corresponding to assessment scales, showing for each range the number of persons of that opinion. In this way, the subjective evaluation may be presented as an average opinion with a standard deviation.