1、 Laboratory testing methods
1. Reverberation chamber method:
-Principle: Using the multiple reflection sound field in the reverberation chamber, measure the sound absorption coefficient of materials within a certain frequency range.
-Steps:
1. Place the egg cotton sample in the reverberation room.
2. Use a sound source to produce sound of a specific frequency.
3. Measure and record the sound pressure level in the reverberation chamber.
4. Remove the egg cotton sample and repeat the measurement.
5. Compare the sound pressure level with and without egg cotton and calculate the sound absorption coefficient.
-Advantages: It can accurately reflect the sound absorption performance of materials in practical use.
-Disadvantage: Requires professional laboratory equipment and environment.
 
2. Standing wave tube method:
-Principle: By generating standing waves inside a standing wave tube, the sound absorption coefficient of the material is measured.
-Steps:
1. Place the egg cotton sample in a standing wave tube.
2. Generate sound waves of a specific frequency to form standing waves.
3. Measure and record the amplitude of standing waves.
4. Remove the egg cotton sample and repeat the measurement.
5. Compare the amplitude with and without egg cotton and calculate the sound absorption coefficient.
-Advantages: Suitable for testing high-frequency sounds.
-Disadvantage: The testing frequency range is limited.
 
2、 On site testing method
1. Acoustic method:
-Principle: Use a sound meter to measure the sound pressure level in the environment and evaluate the sound insulation effect of materials.
-Steps:
1. Install sound sources and sound meters in the testing environment.
2. Make sounds of a specific frequency.
3. Record the sound pressure level with or without egg cotton.
4. Compare the differences between the two and evaluate the sound insulation effect.
-Advantages: Easy to operate, suitable for on-site testing.
-Disadvantage: Due to significant environmental factors, the results may not be accurate enough.
 
2. Transfer function method:
-Principle: By measuring the sound pressure levels of input and output, calculating the transfer function of the material, and evaluating the sound insulation effect.
-Steps:
1. Install sound sources and microphones in the testing environment.
2. Make sounds of a specific frequency.
3. Record the input and output sound pressure levels with or without egg cotton.
4. Calculate the transfer function and evaluate the sound insulation effect.
-Advantages: It can accurately reflect the sound insulation performance of materials.
-Disadvantage: Requires professional testing equipment and operational skills.
 
3、 Subjective evaluation method
1. Auditory test:
-Principle: Subjectively evaluate the sound insulation effect of materials through human auditory perception.
-Steps:
1. Install sound sources in the testing environment.
2. Make sounds of a specific frequency.
3. Record the auditory sensation with or without egg cotton.
4. Compare the differences between the two and subjectively evaluate the sound insulation effect.
-Advantages: It can directly reflect people's feelings in actual use.
-Disadvantages: Strong subjectivity, results may vary from person to person.
 
2. Questionnaire survey method:
-Principle: Collect users' subjective feelings through questionnaire surveys and evaluate the sound insulation effect of materials.
-Steps:
1. Design a questionnaire that includes evaluation items regarding the sound insulation effect.
2. Distribute questionnaires to users and collect feedback.
3. Analyze the questionnaire results and evaluate the sound insulation effect.
-Advantages: It can collect a large number of user feedback and has a certain representativeness.
-Disadvantage: The results may be biased due to questionnaire design and subjective factors of users.
 
In summary, there are various testing methods for the sound insulation effect of egg cotton. Choosing the appropriate testing method requires consideration of the specific testing environment, testing objectives, and available testing resources. Laboratory testing methods are usually more precise, but require specialized equipment and environment; The on-site testing method is easy to operate, but it is greatly affected by environmental factors; Subjective evaluation methods can directly reflect people's feelings, but the results may have subjective biases.