Two studies were made to assess the effects of high‐level noise (1) upon efficiency in speech reception and (2) in causing temporary hearing losses. Over 1400 observers made responses under various sound‐pressure levels for each of 13 different noise spectra. It was found that: (1) Increases in noise level always adversely affected speech reception, while changes in spectra did not always have an effect; time‐in‐noise did not progressively decrease scores. (2) Hearing threshold shifts of 4 to 5 db were found after a 2‐hr noise exposure; certain spectra caused greater threshold shifts than others.