Hiring more than one interpreter is advisable when a proceeding is lengthy, complicated and/or there are multiple defendants requiring interpreter services. “Lengthy” or “complicated” proceedings are ones that last more than two hours, or that will have extensive, complex legal arguments and testimony, such as suppression hearings and some preliminary and sentencing hearings. At least two interpreters should always be used in trials, so that they can work in shifts and avoid fatigue. Interpreting is a very intense activity that requires deep, continuous concentration and effort. Studies have shown that fatigue can occur after as little as 30 minutes and can cause an interpreter to lose their focus, thereby producing an inaccurate or incomplete interpretation. Since the interpreters have sworn to interpret “accurately and completely,” they must avoid fatigue; and since their English interpretation becomes part of the record, the court must take all steps necessary to provide the working conditions necessary to ensure accurate, complete interpretation.
It is not necessary to hire an interpreter for each defendant. Equipment is available (many interpreters have their own) that allows one or two interpreters to “broadcast” interpretation through headsets worn by the non-English speaking participants. Nevertheless, in multiple defendant cases it may be advisable to hire one or two extra interpreters to ensure that someone is always available to interpret for attorney-client communications during the proceeding.
Source: NAJIT.ORG