The goal of the present work is to develop valid measures of listening effort independent of task difficulty. Various markers of effort will be measured for listening conditions of varying difficulty but with equal performance. The experimental task will involve tracking a previously specified keyword(s) in a speech sample. The task difficulty will be manipulated by changing the number of keywords to be tracked and by changing the level of a noise masker so that the signal-to-noise-ratio changes from favorable to unfavorable. The participants will be a group of young normal-hearing individuals. Effort will be measured using several physiological markers such as galvanic skin response, heart rate, and blood oxygen level. Subjective ratings of listening effort will also be collected. For each level of difficulty, the percent correct detection performance will be calculated. Conditions that result in equal performance (for example, greater than 90% scores) will be selected for analyses. Any difference in physiological measures between these conditions will then likely reflect differences in listening effort. The study will provide preliminary candidates for developing an objective and real-time measure of listening effort.