Sound signal generator testing apparatus
A sound signal generator testing apparatus is provided. The apparatus includes a hermetic seal ( 2 ), a sound signal input unit ( 4 ), and at least a noise suppression unit ( 5 ). The sound signal input unit is for receiving sound signals transmitted from a sound signal generator ( 1 ) under testing. Each noise suppression unit includes a sound signal input unit, a low pass filter, an inverter, and an output. The sound signal input unit is for receiving sound signals. The low pass filter is for filtering the sound signals by passing the low frequencies of the sound signals that are below a predetermined value. The inverter is for inverting phases of the sound signals transmitted from the low pass filter and producing inverted sound signals. The output unit is placed behind the sound signal input unit for outputting the inverted sound signals.
1. A sound signal generator testing apparatus, comprising:
a hermetically sealed enclosure;
an acoustical absorbent;
a first sound signal input unit disposed inside of the hermetically sealed enclosure and inside the acoustical absorbent and connected to a testing unit, for receiving sound signals transmitted from a sound signal generator under testing; and
at least a noise suppression unit, comprising:
a second sound signal input unit for receiving sound signals, the second sound signal input unit being disposed outside of the acoustical absorbent;
a low pass filter filtering the sound signals by passing the low frequencies of the sound signals that are below a predetermined value;
an inverter for inverting a polarity of the filtered sound signals;
an output unit being placed behind the second sound signal input unit for outputting the inverted sound signals, the output unit being disposed outside of the acoustical absorbent.
2. The sound signal testing apparatus as described in claim 1 , wherein both of the first sound signal input unit and the second sound signal input unit are microphones.
3. The sound signal testing apparatus as described in claim 1 , further comprising a frequency regulating unit interposed between the inverter and the output unit, for regulating frequencies of the inverted sound signals.
4. The sound signal testing apparatus as described in claim 3 , further comprising a delay unit interposed between the frequency regulating unit and the output unit, for delaying the inverted sound signals for a predetermined delay time before transmitting the inverted sound signals to the output unit.
5. The sound signal testing apparatus as described in claim 4 , wherein the low pass filter connects to the first sound signal input unit for receiving the sound signals received by the first sound signal input unit.
6. The sound signal testing apparatus as described in claim 4 , wherein the low pass filter connects to a sound source for receiving the sound signals, the sound signal source being used to providing sound signals to the sound signal generator.
7. The sound signal testing apparatus as described in claim 4 , wherein the hermetically sealed enclosure comprises a through hole that is defined through a wall of the hermetically sealed enclosure, and holds the sound signal generator therein.