why am i only hearing a piano in exhale by output

The threshold of hearing varies from listener to listener and it also varies with frequency. If the SPL of a signal is below 0 dB SPL it should be inaudible to most listeners. If the SPL of a signal is above 0 dB SPL it should be audible to listeners with normal hearing. The SPL is the ratio of the acoustic level to the threshold of normal hearing at 1 kHz.

When we measure sound pressure levels (SPL) in a room we use a decibel scale. A 1-dB increase in level is just noticeable to most listeners. A 10-dB increase in level is perceived as doubling of volume by most listeners. Our ears respond logarithmically to increases in loudness.

So, does it really matter which units we use?īoth units convey the same information, but the dB scale relates more closely to the way our ears respond. Percent is used to specify ratios on a linear scale. Decibels are used to specify ratios on a logarithmic scale. In distortion measurements, they specify the ratio of the distortion signal to the desired signal. Loudness is Logarithmic, Decibels are Logarithmic, Percent is Linearĭecibels and percent are both ratio units.

Loudness is useful information, and THD ratios are much more meaningful when they are expressed in the same logarithmic terms that we use to quantify loudness. When THD is expressed in terms of dB, we can easily determine how loud the distortion will be in our playback system. As it turns out, this information is much easier to use. If we use decibels we can say that the distortion voltage is a certain number of decibels below the test signal voltage. The specifications tell us that the distortion voltage is a certain percentage of test signal voltage. Unfortunately, distortion measurements are traditionally expressed as a percent. Obviously the 40 dB, 60 dB and 80 dB figures are easier to understand than 1%, 0.1% and 0.01%.

When distortion reaches 0.01% it is 80 dB lower than the music. When distortion reaches 0.1% it is 60 dB lower than the music. When distortion reaches 1% it is just 40 dB lower than the music. The well-trained geek will convert % to dB in order to give meaning to these numbers. 0.01% is 20 dB lower than 0.1% and this is 20 dB lower than 1%. If you are a well-trained geek you will recognize that each added leading zero represents a 20 dB improvement. If you are like most people you just know that 0.001% is the best of the three numbers listed above. But what do 1%, 0.1%, 0.01% or 0.001% mean in terms of loudness or audibility? Distortion measurements (THD, THD+N and IMD) are traditionally expressed in terms of percent.

Why am i only hearing a piano in exhale by output