A hearing assistance device (100; 200) for use by a listener, comprising: a microphone configured to receive sounds from an environment of the hearing assistance device (100; 200) and produce a microphone signal representative of the sounds; a receiver configured to produce output sounds based on an output signal and transmit the output sounds to the listener; and a processing circuit (106; 206) configured to produce the output signal by processing the microphone signal, the processing circuit (106; 206) including: a plurality of functional modules, wherein each functional module is configured to have a dynamically adjustable calculation rate for executing a particular set of calculations, wherein the calculation rate specifies how often the particular set of calculations is executed by the functional module, and wherein the plurality of functional modules includes a feedback cancellation module and a directionality control module; an auditory environment condition detector configured to detect one or more auditory condition values indicative of one or more auditory environment conditions each related to an amount of computation needed by one or more functional modules of the plurality of functional modules to each perform at a performance level that meets one or more predetermined criteria; and a computational resource allocator (110; 210) configured to dynamically adjust the one or more calculation rates of the corresponding one or more functional modules based on the one or more auditory condition values, wherein in response to an auditory condition value indicating the environment to be quiet, the computational resource allocator dynamically adjusts the calculation rate of the feedback cancellation module to increase while the calculation rate of the directionality control module decreases, and in response to an auditory condition value indicating the environment to be louder than when the environment was quiet, the computational resource allocator dynamically adjusts the calculation rate of the directionality control module to increase while the calculation rate of the feedback cancellation module decreases. a microphone configured to receive sounds from an environment of the hearing assistance device (100; 200) and produce a microphone signal representative of the sounds; a receiver configured to produce output sounds based on an output signal and transmit the output sounds to the listener; and a processing circuit (106; 206) configured to produce the output signal by processing the microphone signal, the processing circuit (106; 206) including: a plurality of functional modules, wherein each functional module is configured to have a dynamically adjustable calculation rate for executing a particular set of calculations, wherein the calculation rate specifies how often the particular set of calculations is executed by the functional module, and wherein the plurality of functional modules includes a feedback cancellation module and a directionality control module; an auditory environment condition detector configured to detect one or more auditory condition values indicative of one or more auditory environment conditions each related to an amount of computation needed by one or more functional modules of the plurality of functional modules to each perform at a performance level that meets one or more predetermined criteria; and a computational resource allocator (110; 210) configured to dynamically adjust the one or more calculation rates of the corresponding one or more functional modules based on the one or more auditory condition values, wherein in response to an auditory condition value indicating the environment to be quiet, the computational resource allocator a plurality of functional modules, wherein each functional module is configured to have a dynamically adjustable calculation rate for executing a particular set of calculations, wherein the calculation rate specifies how often the particular set of calculations is executed by the functional module, and wherein the plurality of functional modules includes a feedback cancellation module and a directionality control module; an auditory environment condition detector configured to detect one or more auditory condition values indicative of one or more auditory environment conditions each related to an amount of computation needed by one or more functional modules of the plurality of functional modules to each perform at a performance level that meets one or more predetermined criteria; and a computational resource allocator (110; 210) configured to dynamically adjust the one or more calculation rates of the corresponding one or more functional modules based on the one or more auditory condition values, wherein in response to an auditory condition value indicating the environment to be quiet, the computational resource allocator dynamically adjusts the calculation rate of the feedback cancellation module to increase while the calculation rate of the directionality control module decreases, and in response to an auditory condition value indicating the environment to be louder than when the environment was quiet, the computational resource allocator dynamically adjusts the calculation rate of the directionality control module to increase while the calculation rate of the feedback cancellation module decreases.