The most important figures  from which useful results can be extracted are the figures 5 and 6. These are frequency-timespectra, called spectrograms, representing the peaks of the energy-frequencyspectra as a function of time. In these figures, no energy levels areindicated. However, dark bands represent predominantly high energy regions andwhite patches represent almost zero energy. The level of grey colour is anindicator of the relative levels of energy.
Spectrograms are used to  separate the characteristicsof the voice from those of words. The lowest frequency, which is thebottom-most line in these figures, indicates the pitch, which is acharacteristic of the voice. Since the male voice has a lower pitch compared tothe female voice, it also has a lower fundamental frequency. In the presentcase, the ratio of the fundamental frequencies of the male and female voices isabout 1:2, which is the usual case.
The male voices in the  present cases havealso a larger number of subharmonics than the female voices, before the energydrops off to negligible values. This is a typical feature of the human voice,which is due to the difference in structure of the voice- producing mechanism.
A detailed study of all the  spectrogramsshowed that the two male voices had the fundamental frequencies of 108 Hz and118 Hz. The corresponding values for the female voices were 237 Hz and 242 Hz.In the case of A, both the male voices show 11 subharmonics, whereas both thefemale voices show 6 subharmonics. In the case of U, the two male voices show 7subharmonics, but the female voices have only 1 subharmonic. For Ma, the numberof subharmonics for the male and the female voices was respectively 3 and 1.
A more interesting result  is that for Om.This signal has two segments, starting with O and gradually tapering off to M.From the point of view of intonation and the shape and the cavity of the mouth,the sound O is in between the sounds A and U. This was clearly seen in all thefour figures for Om, of which only two are presented in figures 5 and 6. Themale voices show 9 subharmonics in the region of O and 2 in the region of M. Inthe case of the female voices, these are 4 for O and 1 for M. Thus, it is clearlyseen that the sound pattern for O in all cases lies between those for A and U.In the second segment, all sound patterns agree with those recorded earlier forM.

There is an internal  consistency in the data,which testifies to its authenticity and reliability.

 

It has thus been possible  to identify the.fundamental and subharmonics for the sound patterns A, U, Ma and Om, accordingto the Sanskrit pronunciation.
Where is a work of this  type useful? Considerthe two investigations referred to earlier in Jina Devi2 and Uchida& Yamamoto8. These two were done almost at the same time, butindependently of each other. But a comparison between them is almostimpossible, because the sound patterns used by the two groups cannot becompared. It is only when the spectrograms are properly analysed and the soundcharacteristics properly identified, does a comparison become meaningful. Byrecording the sound patterns and extracting their frequency characteristics, one can identify that frequency which has the most noticeable effect on seed germination and only then does a comparison become possible.

It is proposed to analyse  in a future studythe Agnihotra mantra spectrally and to use this information in germination studies.