Active sound effect generating apparatus

An active sound effect generating apparatus comprising:

• a waveform data table that stores a waveform data corresponding to one waveform period;
• a rotational frequency detecting unit that detects a rotational frequency of an engine;
• a reference signal generating unit that generates a reference signal having a harmonic in accordance with the rotational frequency by sequentially reading the waveform data from the waveform data table;
• a control signal generating unit that generates a control signal used for generation of a sound effect on the basis of the reference signal;
• an output unit that outputs the control signal as the sound effect;
• an amount-of-change-in-rotational-frequency calculating unit that calculates an amount of change in the rotational frequency of the engine, which is a time differential value of the rotational frequency;
• an engine load detecting unit that detects a load of the engine;
• and
• a vehicle speed detecting unit that detects a vehicle speed,
• wherein the control signal generating unit adjusts an amplitude of the control signal by varying an amplitude of the reference signal in accordance with the amount of change in rotational frequency, the load of the engine, and the vehicle speed such that the amplitude of the control signal is set so as to be decreased with the decreasing vehicle speed detected by the vehicle speed detecting unit.

An active sound effect generating apparatus comprising:

• a memory device storing a waveform data table that stores a waveform data corresponding to one waveform period;
• a vehicle speed detector that detects a vehicle speed;
• a frequency setting circuitry that sets a vehicle-speed-corresponding frequency, which is a frequency corresponding to the vehicle speed detected by the vehicle speed detector;
• a reference signal generating circuitry that generates a reference signal having a harmonic in accordance with the vehicle-speed-corresponding frequency by sequentially reading the waveform data from the waveform data table;
• a control signal generating circuitry that generates a control signal used for generation of a sound effect using the reference signal;
• an output circuitry that outputs the control signal as the sound effect;
• an amount-of-change-in-frequency calculating circuitry that calculates an amount of change in frequency, which is a time differential value of the vehicle-speed-corresponding frequency;
• and
• a driving source load detector that detects a load of a driving source of a vehicle,
• wherein the control signal generating circuitry adjusts an amplitude of the control signal by varying an amplitude of the reference signal in accordance with the amount of change in frequency and the load of the driving source.